Earliest service group that user mode applications can use in Windows? - windows

In Windows, there are a lot of different groups for services. the earliest one is System reserved.
So can user mode services use any of them? or is there a limit for user mode applications?
For example i wrote a test app that writes/reads files, obviously this shouldn't work in the first group (System reserved) since file system drivers are not yet loaded (?), but it does work, so i thought maybe Windows is not executing it in that group since its a user mode app?

Related

How to install my program on windows startup

I'm trying to figure out how to install software when the PC reboots Note that this is on machine startup, not user login. Anyone have any suggestions? Google searches just return how to set programs to start on user login. That's not what I need.
You have a few puzzle pieces to unravel here:
Choosing a mechanism for running on startup prior to user login. For this, the fact that your task is installation of further software doesn't matter. A "service" is the usual way to do this, although for example antivirus software tends to use device drivers.
Automating scheduling your code to run at startup. If you chose a service in the above step, this means using the Service Control Manager API.
Actually doing the work, without having an active user login session. Services run in an environment where there is no UI available, the user registry is associated with a service account and not any real user, etc. Other than that, code runs normally (you can load DLLs, access files and directories, etc). Permissions needed by your installer may also become a problem and cause you to modify the service installation options in step 2.

Can Window OS handle multiple user same time as unix

As we know UNIX is a computer Operating System which is capable of handling activities from multiple users at the same time. My question is that can windows have same capability? If 'yes' then 'how'?
That depends upon your definition of "multiple users".
Processes can (and do) run under multiple user accounts all the time on all modern Windows systems (in this definition, I'm excluding the 95/98/ME line). This has been the case since at least NT 4.
Running multiple interactive user GUI sessions simultaneously, however, is restricted to specific editions of Windows (Server, Terminal Services, etc.). It's not so much a technical limitation as it is a licensing limitation. I'm unaware of limitations on the number of concurrent remote PSSessions supported by Windows (licensing- or technical-based).
Yes. Login using "user1". Run app with admin rights: it runs in "administrator" user group at a same time.

How to find out what permission an application needs under Windows 7

Is there a way to find out what privileges my application needs in order to run in a Windows 7 environment?
I have a Delphi application that is using BDE and ODBC for database connectivity. This application works on most computers with Windows 7 running on a normal user account. However on some computers it only works on accounts with administrative privileges and is not working correctly on normal user accounts. I suspect it's a permission problem. The computers also are running in Active Directory.
I tried to find some informations using Process Monitor from SysInternals, however the output for me is too advanced. The process monitor log for two runs of my app (1. successful with administrative rights, 2. unsuccessfull on normal rights) had over 22k lines and i could not find the answer (needle) in the process monitor log (haystack).
What could i do to determine the privileges that my app needs in windows 7?
Use the Standard User Analyzer from the Microsoft Application Compatibility Toolkit.
The Standard User Analyzer (SUA) tool and the Standard User Analyzer
Wizard (SUA Wizard) both enable you to test your applications and to
monitor API calls in order to detect potential compatibility issues
due to the User Account Control (UAC) feature in the Windows® 7
operating system.
UAC, formerly known as Limited User Account (LUA), requires that all
users (including members of the Administrator group) run as Standard
Users, until the application is deliberately elevated, by using the
security prompt dialog box. However, not all applications can run
properly with the Standard User role, due to the application requiring
access and privileges for locations that are unavailable to a Standard
User.
Aaron Margosis has a tool called LUA Buglight that is designed to help track down issues related to privileges.
You can download the latest version from this blog post:
LUA Buglight 2.1.1 with support for Win7/2008R2 SP1
It is similar in concept to the MS Application Verifier. However, in practice I found LUA Buglight much easier to use and understand. Same with ProcessMonitor. It will monitor your process in a similar way but only report actions that failed as a normal user but succeeded as a admin user.
There is no documentation but it is simple to use. From the main GUI window select your Exe and let the BugLight program launch it. You need to be running in an Admin account with UAC enabled. Run your program though the steps that fail when you are not an admin. When you are done click on the Stop Logging button to see a report that lists what calls would have failed without admin rights.

How to test Windows library under different user-security permutations?

I am working on a developer library that I want to release later this year and it should work under different user rights and also on different windows platforms. The library can be executed in both a web, windows-service and desktop-app-client context.
What combinations of users should I test the application under? Is it enough to test it using
Normal standard user
Administrator
Local system account
Are there any more permutations of users? What kind of typical users/policies do exists out in the enterprises?
Are there any guides about how to Windows "test" software before release so that the number of security/rights gotchas/issues can be addressed before the application hit the customers?

Run a script on Windows startup without a user logged on

This is a Windows 2003 (or later) machine that gets switched on every morning, but no one logs on until some hours later.
I want to use the time in between to run a backup script c:\script\backup.cmd
How can I start this unattended after the machine has come up?
I tried 2 registry keys, but this resulted in the script being run after a user logs on (which is too late):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
In the end I used Windows TaskScheduler, who has such an option, but I was wondering if there is another possibility?
Short answer: GPEDIT.MSC (Start, Run, GPEdit.msc)
Windows 2000 and above [1] offer a computer Startup Scripts collection in the policy editor:
Computer Settings -> Windows Settings -> Scripts (Startup/Shutdown)
There's an equivalent logon script area (i.e. after computer startup, when a user logs on) in the User configuration bit.
Longer:
GPEDIT.MSC is the Group Policy editing console, and runs against the local computer's Local Group Policy store when it's used directly, so it's useful for setting local-only parameters. When using Active Directory, a similar interface is used to edit AD Forest-hosted group policy objects (GPOs), so the same settings are available across a bunch of machines.
The computer startup scripts run in the computer context, i.e. as LocalSystem, as you noted, so they often can't access network drives which require a certain user or group membership to work. When domain-member computers access network resources, they generally (with exceptions) authenticate using their MACHINENAME$ account - which lets you set Share/NTFS permissions to allow a computer to access those resources.
A startup script is a quick and easy way of getting a process running when the machine boots.
The computer startup process will be affected by the time it takes to run the program, though, so you might want to ensure you call it with the START command from a batch file, or specifying not to wait for the executable to complete in whatever script language you use. (the key point there is: run the script asynchronously unless it's critical, or doesn't need to be run asynchronously cos it will always take no time at all. Long boots = unhappy users).
Using a Win32 Service is an alternative option - you can use the SRVANY utility from the Resource Kit to "service-ify" pretty much any executable. VS.Net 2002 and later also let you build a managed service directly.
And Task Scheduler gets much more capable as of Vista/2008, able to run scripts at startup, on idle, and/or when Event Logs are generated or certain other conditions are met: it's pretty cool! Scheduled Tasks has the possible advantage of being able to specify the user account under which the task runs, if that's important to you.
Caveat Scriptor:
http://support.microsoft.com/kb/256320
Run Startup Scripts Asynchronously:
http://msdn.microsoft.com/en-us/library/ms811602.aspx
Vista Task Scheduler (what's new):
http://technet.microsoft.com/en-us/appcompat/aa906020.aspx
[1] Windows XP, 2003, Vista/2008, Windows 7/2008R2, Windows 8/2012, Windows 8.1/2012R2, Windows 10/Windows Server 2016. Everything. But NT4 didn't!
You have already outlined a good solution:
Setup a scheduled task to run at Start Up and allow the job to run when the user isn't logged on.
You can run a script at system startup using group policy gpedit.msc
The way you aleady do this seems fine to me; however if you want an alternative approach then services get started when the machine boots so you could write a service that detects if it's a new day (to allow for reboots) and if it is then run your backup.
If I was doing this as a service I'd use TCL because I know it and like it and it has an extension twapi that allows you to run a script as a service. Other scripting languages may well have similar facilities.
There is, if you're using Active Directory. If you can isolate the computer to its own OU or use WMI filtering, you could assign a GPO which has a startup script for the computer. This would ensure that even if someone went in via safe mode and disabled the Task Scheduler, upon startup and connection to the domain, the script would run.

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