Problems reading registry from Delphi 7 on Windows 7 64 bit - windows

Question

I think this question was already asked, but I couldn't find a solution which works for me. I use Delphi 7 under Windows 7 Ultimate, 64 bit. Actually I started writing application under 32 bit OS, but then changes PC, so now its 64. In my program I use registration process with Licence ID generated from PROGID value of Windows. Unfortunately it doesn't read the value, seems like it is looking in a different folder, probably redirected by Windows 64 to 32 bit registry. Can you help? This is the code I use:
Registry := TRegistry.Create(KEY_READ OR $0100);
try
Registry.Lazywrite := false;
Registry.RootKey := HKEY_LOCAL_MACHINE;
if CheckForWinNT = true then
Begin
if not Registry.OpenKeyReadOnly('\Software\Microsoft\Windows NT\CurrentVersion') then showmessagE('cant open');
end
else
Registry.OpenKeyReadOnly('\Software\Microsoft\Windows\CurrentVersion');
result := Registry.ReadString('ProductID');
Registry.CloseKey;
finally
Registry.Free;
end; // try..finally
Also, do you know how to find whether program is running under 64 bit or 32 bit computer in Delphi 7?

Answer 1

You already asked this question see Registry ReadString method is not working in Windows 7 in Delphi 7.
So you know that you have to add $0100 in the TRegistry.Create. The problem with your code is that you use OpenKeyReadOnly which resets the Access property of the registry to KEY_READ, so KEY_READ or $0100 is lost.
Just use OpenKey instead of OpenKeyReadOnly, this won't reset your Access property.

Answer 2

Here is some Delphi 7 code to detect whether you are running in a 64-bit OS:
function Is64BitOS: Boolean;
type
TIsWow64Process = function(Handle:THandle; var IsWow64 : BOOL) : BOOL; stdcall;
var
hKernel32 : Integer;
IsWow64Process : TIsWow64Process;
IsWow64 : BOOL;
begin
// we can check if the operating system is 64-bit by checking whether
// we are running under Wow64 (we are 32-bit code). We must check if this
// function is implemented before we call it, because some older versions
// of kernel32.dll (eg. Windows 2000) don't know about it.
// see http://msdn.microsoft.com/en-us/library/ms684139%28VS.85%29.aspx
Result := False;
hKernel32 := LoadLibrary('kernel32.dll');
if (hKernel32 = 0) then RaiseLastOSError;
#IsWow64Process := GetProcAddress(hkernel32, 'IsWow64Process');
if Assigned(IsWow64Process) then begin
IsWow64 := False;
if (IsWow64Process(GetCurrentProcess, IsWow64)) then begin
Result := IsWow64;
end
else RaiseLastOSError;
end;
FreeLibrary(hKernel32);
end;
(Shamelessly plagiarized from myself, here)
It looks like you are passing KEY_WOW64_64KEY ($0100), so you should be looking at the 64-bit registry branch. If you want to look at the 32-bit registry branch, you should pass KEY_WOW64_32KEY ($0200).

Answer 3

As to your side question, whether it's a 64-bit computer (which is not the same thing as running on a 64-bit OS), have a look at the answers to this question.

Answer 4

I know this topic is about delphi 7, but I thought I was having problems reading the registry and came here to learn.. I ended up using Key_Read instead of all the extras suggested here.
I'm using Delphi 2010 and I used Key_Read just fine.
Here is my part of my source that works:
//Search registry
reg:=TRegistry.Create(KEY_READ);
with reg do begin
try
RootKey := HKEY_LOCAL_MACHINE;
if OpenKey('\SOFTWARE\Wow6432Node\Blizzard Entertainment\World of Warcraft',false) then
begin
memo.Lines.Add('HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Blizzard Entertainment\World of Warcraft - exists');
wowdir1 := readstring('InstallPath');
memo.Lines.Add('InstallPath - ' + wowdir1);
newline;
closekey;
end;
if OpenKey('\SOFTWARE\Wow6432Node\Blizzard Entertainment\World of Warcraft',false) then
begin
memo.Lines.Add('HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Blizzard Entertainment\World of Warcraft - exists');
wowdir2 := readstring('GamePath');
memo.Lines.Add('GamePath - ' + wowdir2);
newline;
wowdir1 := readstring('');
closekey;
end;
if OpenKey('\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\World of Warcraft',false) then
begin
memo.Lines.Add'HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall\World of Warcraft - exists');
wowdir3 := readstring('InstallLocation');
memo.Lines.Add('InstallLocation - ' + wowdir3);
newline;
wowdir1 := readstring('');
closekey;
end;
finally
reg.Free;
end;
I tried the other Keys that are displayed here and found I don't need KEY_WOW64_64KEY OR KEY_WOW64_32KEY. This must have been a bug that has been corrected in Delphi 2010.