What is this GUID? - windows

After connect a network-drive, when we open a Windows Explorer or a File Dialog,
the process find this key in the registry to show it's volume name.
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{A45BA3B2-F3
96-4F67-8375-ECC2CA1EBBFC}\_LabelFromReg
I don't know what the GUID is.
What is it?
Who(When) does create the key?
How does the application(in this case, Windows Explorer) know the key?
I'm developing a network-redirector like SMB.
I should write a volume name to the key.
Once my network volume connected, the registry key also created. (of cource the GUID is different with SMB's. It even changes whenever each connection created and deleted)
But I don't know how I can get the my volume's(?) GUID.(Even who creates the key)
I tried to find DefineDosDeviceW(suspected) in ReactOS source. But it hasn't implemented yet. T.T
-Of course, I also write the volume name to \MountPoints2\##UNCNAME\_LabelFromReg
But it doesn't work for WOW64 applications in 64Bit Windows.

This is not a specific GUID; it's a volume identifier. Windows Explorer creates these keys when volumes are mounted. You can see a list of currently mounted volume IDs by running mountvol without parameters. Programmatically (on Win32 level), you can obtain it with FindFirstVolume and friends. I don't know anything about network redirector; however, it doesn't seem right to poke within Explorer registry key manually. It's Explorer's private territory. What are you trying to accomplish? Maybe there is a documented API for that.

Related

Drive mapping unavailable when added via registry

I want to add drive mapping from my c# app for specific user on remote machine. I'm trying to do it by adding new registry key.
When I add new drive mapping in registry, adding new key in:
HKEY_USERS\< USER >\Network
so, for example, to map \some_path\all under R:\ I make new key:
HKEY_USERS\< USER >\Network\R
with following values:
such added drive is visible when I type
net use
in command line, but it's status is "Unavailable". It becomes "OK" after computer restart(and it's visible in Windows Explorer).
How can I achieve it without restarting computer? What process during restart changes drive status and makes it visible in Windows Explorer?
Or another approach: when i type add drive via:
net use R:\ \\some_path\all
it's immediately available in Windows Explorer and visible after net use command. What net use does beside adding new key to registry(as presented above)?

Add explorer context menu item for PDF files from delphi

I have my application written in Delphi XE that works with PDF files. Applicaiton is Win32. On start I would like to ensure that there is my item in explorer context menu for PDF files. I would like to be able to specify whether it should be added for active user only or for all users (with UAC I will need to restart with Admin privileges but thats ok).
I started with How to associate a Delphi program with a file type, but only for the current user? and How to add item to windows explorer content menu in delphi? . I tested it with manual registry editing via regedit and it worked fine for "new" extensions. But for .pdf it is more complicated as it will be most probably already present in the registry.
On my PC the .pdf key is referencing AcroExch.Document . But adding shell/something subkey to the AcroExch.Document key is not working because it has CurVer subkey referencing to AcroExch.Document.7. However another PC with another verison of Acrobat had this names a little different. It is no problem for me to follow the CurVer reference but is that a correct approach? And what about situation where no PDF reader is installed, how should I name my keys so Acrobat won't overwrite them when installed?
But more pressing matter is in which root should I put my keys? How to associate a Delphi program with a file type, but only for the current user? is mentioning HKLM (Local Machine) and HKCU (Current user). Its seems rather straightforward but I am unable to set values in HKLM from Delphi. Strangely I can create keys:
var reg:TRegistry;
key := '\Software\Classes\'+keyname+'\shell\'+name+'\command';
reg.CreateKey(key);
but I am getting Access Denied when trying to write the actual value:
reg.OpenKey(key,false);
reg.WriteString('',command);
I am getting the same Access Denied exception even on WinXP, no matter if the applicaiton is running as Admin (Win7), I even tried to set permissions (Everyone full control) for the key via regedit (I can edit the value via regedit without problems). I tried creating the registry with different access modes, all with no luck:
reg := TRegistry.Create(KEY_WRITE or KEY_WOW64_64KEY);
reg := TRegistry.Create(KEY_ALL_ACCESS or KEY_WOW64_64KEY);
reg.Access := KEY_ALL_ACCESS;
reg.Access := KEY_WRITE or KEY_WOW64_64KEY;
reg.Access := KEY_ALL_ACCESS or KEY_WOW64_64KEY;
With HKCU everything works fine.
So I tried writing into HKEY_CLASSES_ROOT and it works and actually puts the keys exactly where I want (into HKLM) if running as Admin. But according to http://msdn.microsoft.com/en-us/library/windows/desktop/ms724475.aspx
The HKEY_CLASSES_ROOT (HKCR) key contains file name extension associations and COM class registration information such as ProgIDs, CLSIDs, and IIDs. It is primarily intended for compatibility with the registry in 16-bit Windows.
I do not like the note about the primary purpose being compatibile with 16-bit Windows. And the actual conditions where the changes will be written is more complicated than I would like.
So basically I have these questions:
What is the advantage of using AcroExch.Document and CurVer instead of pointing directly to AcroExch.Document.7? And what are the "best manners" when adding my keys into this structure? What about the case when the .pdf is not yet associated with anything?
Where should I put my keys and why I am not able to write into HKLM?
Edit:
The problem with Access Denied when writing to HKLM was caused by my error. I did use in previous code openKeyReadOnly and I did not notice that it will swtich the Access property to readonly for all subsequent calls.
To answer your other question, if Adobe is not installed yet then obviously the PDF keys will likely not exist in the Registry yet so you would have to create your own .pdf and ProgID keys so that you can attach your Shell command on it. If Adobe is installed afterwards, it is likely going to wipe out your keys and replace them with its own, so you would have to recreate your Shell command within Adobe's key structure. Your app can query the Registry to check for that condition periodically, such as at startup.
You have asked two separate questions. Since I know the answer to one and not the other, I'm going to answer just one. For future reference, I do recommend that you ask a single question at a time.
Where should I put my keys?
You are correct in discerning that you should not use HKCR. The documentation for HKCR says:
Class registration and file name extension information is stored under
both the HKEY_LOCAL_MACHINE and HKEY_CURRENT_USER keys. The
HKEY_LOCAL_MACHINE\Software\Classes key contains default settings that
can apply to all users on the local computer. The
HKEY_CURRENT_USER\Software\Classes key contains settings that apply
only to the interactive user. The HKEY_CLASSES_ROOT key provides a
view of the registry that merges the information from these two
sources. HKEY_CLASSES_ROOT also provides this merged view for
applications designed for previous versions of Windows.
....
If you write keys to a key under HKEY_CLASSES_ROOT, the system stores
the information under HKEY_LOCAL_MACHINE\Software\Classes. If you
write values to a key under HKEY_CLASSES_ROOT, and the key already
exists under HKEY_CURRENT_USER\Software\Classes, the system will store
the information there instead of under
HKEY_LOCAL_MACHINE\Software\Classes.
So, it is reasonable to use HKCR for reading, but for writing you typically need to exert control over whether to write to HKLM or HKCU. And that means that you cannot write to HKCR.
So, write to HKLM\Software\Classes for machine-wide settings, and HKCU\Software\Classes for user-specific settings.
Note that in Windows 7 and later neither of these keys is redirected and so you do not need to worry about using KEY_WOW64_64KEY. However, in Vista and XP64, and the equivalent server editions, these keys are redirected and reflected. Which means that it might be prudent to use KEY_WOW64_64KEY.

VB6 Application on Windows 7 Cannot Access Mapped Drives

I have a VB6 application which links to several POS terminals from a Windows 7 32-bit machine. The POS terminals are mapped to the Windows 7 machine and I can access the POS terminals from the Windows 7 machine from Explorer or via the cmdline/shell.
The application has been updated to ADO 2.8 and all other controls and components I no longer had source code for have been re-written. After a few annoying hiccups, I got the application to recompile on the Windows 7 computer without errors.
Now come the problems. The VB6 application cannot see or navigate to any mapped drives! I have tried twiddling UAC settings; I have set the app to run in Windows XP SP3 mode; I have tried running as Administrator. None of these things (and many permutations of these) work.
Any suggestions on how to make this work?
Adding this registry setting solved the problem for me: http://technet.microsoft.com/en-us/library/ee844140%28v=ws.10%29.aspx.
To work around this problem, configure the EnableLinkedConnections
registry value. This value enables Windows Vista and Windows 7 to
share network connections between the filtered access token and the
full administrator access token for a member of the Administrators
group. After you configure this registry value, LSA checks whether
there is another access token that is associated with the current user
session if a network resource is mapped to an access token. If LSA
determines that there is a linked access token, it adds the network
share to the linked location. To configure the EnableLinkedConnections
registry value
Click Start, type regedit in the Start programs and files box, and
then press ENTER.
Locate and then right-click the registry subkey HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.
Point to New, and then click DWORD Value.
Type EnableLinkedConnections, and then press ENTER.
Right-click EnableLinkedConnections, and then click Modify.
In the Value data box, type 1, and then click OK.
Exit Registry Editor, and then restart the computer.
I believe you are having trouble because casual drive mapping is per-user, and on a UAC system Administrators group users have two separate contexts (one for each token: SU & elevated).
There is such a thing as a system level drive mapping, which is one done under the System user (NT Authority\System). When you map a drive under this account, and map it persistently, all users can see and use the mapping (subject to the usual access rights for files there).
The normal way you do this is via Domain-level GPOs (Group Policy Objects), which means bribing your local box jockeys if in a corporate managed LAN environment.
One way to do this in a Workgroup machine is to map the letter as System via the AT command, from an elevated command prompt:
at 8:53 am "net use m: \\MediaShare\MyLibrary
ThePW /user:MediaShare\TheUser /persistent:yes > nul"
There the remote server is MediaShare, user TheUser, password ThePW, and 8:53 AM is a minute or two in the future to avoid accidentally scheduling this for tomorrow.
But this fails on Vista and later due to Session 0 Isolation!
So... use the 3rd alternative at Run CMD.exe as Local System Account which is the same thing mentioned by ForcePush's reply to How to map a network drive to be used by a service.
I believe that's what you are after here.
don't know if you ever figured this one out but for me it was the ChDir command (even with the registry fix above).
I had in my code
ChDir "P:\Temp\VidCap\Cam1\" 'I almost never use ChDir
Open "list.txt" For Output As #1
and all the VB6 inbuilt file commands looked straight though any operations, no errors, no nothing. I solved it by explicitly having the path, (in my code it was in a string but you could have it explicitly):
dd = "P:\Temp\VidCap\Cam1\"
Open dd & "list.txt" For Output As #1
works as expected.
hope this helps
H
Try this:
Open command prompt as administrator, and type this in:
net use Z: \\IP Address\share /user:you passwd /persistent:Yes
Change "IP Address", the "share" name, and your username and password as needed.
The author of this is howtogeek (source).
I had same problem. VB6 kept crashing when trying to access USB and mapped drives using the Commondialog method, even though the drives and files were all accessible OK via Explorer. Problem is the drives were not set as shared.
Solved by selecting the connected USB drive in explorer and then right click to
select Properties.
Select Sharing Tab
Select Advanced Sharing
Set the sharing and user rights as needed. May need to have local admin rights.

Sharing data between users with the Windows 7 registry

I have a program that was written on XP. What I've found out is that it doesn't work properly on Win7 because HLKM is no longer writable by non-admins.
Essentially, when you register the program, the licensing information is supposed to go into the registry. That information is valid for everyone on the computer, not just the one user, so I don't want to put it in HKCU. But any copy of the program needs to be able to edit that registry (even if it's a non-admin running it), because there are certain situations when it's going to go get updated license information from my web server (for example, if the registry data is lost or damaged, or if your current license is expired and it needs to see if we've applied an extension).
It's not horrible if it goes out to the web server for every unique user who starts up the program, but it causes some annoying issues, so I'd rather it continue to work the way it did in XP. Is there a way to store data in the registry and still have it shared under Win7, or am I going to have to start looking at storing an INI file on the drive?
Here is how I would architect it: your setup runs elevated and sets up the key. Then if their licensing gets corrupted or whatnot, you enable a button or menu item that has text like "fix license" or "update license". You put a shield on that button or menu item. When they click it, you launch a separate exe using ShellExecute. That exe has a manifest that requires elevation. It can then write to the protected area of the registry. The rest of the app can have a manifest with asInvoker.
If you want it to be completely invisible, either the whole app must always run elevated (annoying) or sometimes the app will just launch another exe that asks for elevation without warning - in which case the smart users will say no. A little less invisibility is a good thing imo.
Could you get the installer to make your particular area of the registry to be writeable by everyone? The installer will need to be run with elevated privileges anyway, I'd expect - so this would seem an ideal approach.

Find out who is locking a file on a network share

I want to known who is locking a file on a network share.
Here is the problem : the network share is on a NAS, so I can't log on. I need a tool to find out remotely who is locking the file. It is not practical to reboot the NAS every time, because there are several users.
Handle.exe, Process Explorer and PsFile seems to be limited to files on the local machine, so they don't work for me.
Just in case someone looking for a solution to this for a Windows based system or NAS:
There is a built-in function in Windows that shows you what files on the local computer are open/locked by remote computer (which has the file open through a file share):
Select "Manage Computer" (Open "Computer Management")
click "Shared Folders"
choose "Open Files"
There you can even close the file forcefully.
On Windows 2008 R2 servers you have two means of viewing what files are open and closing those connections.
Via Share and Storage Management
Server Manager > Roles > File Services > Share and Storage Management > right-click on SaSM > Manage Open File
Via OpenFiles
CMD > Openfiles.exe /query /s SERVERNAME
See http://technet.microsoft.com/en-us/library/bb490961.aspx.
PsFile does work on remote machines. If my login account already has access to the remote share, I can just enter:
psfile \\remote-share
(replace "remote-share" with the name of your file server) and it will list every opened document on that share, along with who has it open, and the file ID if I want to force the file closed. For me, this is a really long list, but it can be narrowed down by entering part of a path:
psfile \\remote-share I:\\Human_Resources
This is kind of tricky, since in my case this remote share is mounted as Z: on my local machine, but psfile identifies paths as they are defined on the remote file server, which in my case is I: (yours will be different). I just had to comb through the results of my first psfile run to see some of the paths it returned and then run it again with a partial path to narrow down the results.
Optionally, PsFile will let you specify credentials for the remote share if you need to supply them for access.
Lastly, a little known tip: if someone clicks on a file in Windows Explorer and cuts or copies the file with the intent to paste it somewhere else, that act also places a lock on the file.
If its simply a case of knowing/seeing who is in a file at any particular time (and if you're using windows) just select the file 'view' as 'details', i.e. rather than Thumbnails, tiles or icons etc. Once in 'details' view, by default you will be shown;
- File name
- Size
- Type, and
- Date modified
All you you need to do now is right click anywhere along said toolbar (file name, size, type etc...) and you will be given a list of other options that the toolbar can display.
Select 'Owner' and a new column will show the username of the person using the file or who originally created it if nobody else is using it.
This can be particularly useful when using a shared MS Access database.
The sessions are handled by the NAS device. What you are asking is dependant on the NAS device and nothing to do with windows. You would have to have a look into your NAS firmware to see to what it support. The only other way is sniff the packets and work it out yourself.
Partial answer: With Process Explorer, you can view handles on a network share opened from your machine.
Use the Menu "Find Handle" and then you can type a path like this
\Device\LanmanRedirector\server\share\
sounds like you have the same problem i tried to solve here. in my case, it's a Linux fileserver (running samba, of course), so i can log in and see what process is locking the file; unfortunately, i haven't found how to close it without killing the responsible session. AFAICT, the windows client 'thinks' it's closed; but didn't bother telling the fileserver.
Close the file e:\gestion\yourfile.dat, open by any user (/a *)
openfiles /disconnect /a * /op "e:\gestion\yourfile.dat"
more in:
http://dosprompt.info/commands/openfiles.asp

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