Chris Mullins said:
If you're trying to figure out, "Am I running in 32 bit mode on a 64
bit machine?" then things are a bit harder. For instance, it bit us in
an installer which did some registry settings stuff, and ended up with
Windows-On-Windows issues
That's exactly right, which is why WMI is the right way to do it.
I think you misunderstood what I meant. Telling which OS and which
architecture you're running on are pretty easy, really. Knowing what to
do with that data is pretty hard.
For example, if you write to the registry from a 32 bit app, then try to
read back the same key in a 64 bit app, you'll get totally different
data. This is due to the Wow6432Node, which does some tricky things that
you just have to know about.
This is the result of the "virtualization" of the registry, done when
running "legacy" 32 bit interactive applications under WOW64.
64 bit applications never run virtualized, nor do 32 or 64 bit services
and drivers.
Disabling "virtualization" will be done by default when using the Orcas
csharp compiler (and with the upcomming SP1 of Framework V2), pre-Orcas
CSC buids should include a manifest by running mt.exe in order to disable
"virtualization".
You can check whether "virtualization" is effective by inspecting the
access token of the current (non-impersonating) user like this:
[DllImport("advapi32.dll", EntryPoint = "GetTokenInformation",
SetLastError = true)]
static extern bool GetTokenInformationNative(
IntPtr TokenHandle,
int TokenInformationClass,
ref int TokenInformation,
int TokenInformationLength,
out int ReturnLength);
public bool IsVirtualized(IntPtr token)
{
bool virtualized = false;
int len = 4;
int info = 0;
if (!GetTokenInformationNative(token, 24, ref info, len, out
len)) // 24 = TokenVirtualizationEnabled
{
string s = "Win32 error " +
Marshal.GetLastWin32Error().ToString();
throw new Exception(s);
}
if(info != 0)
virtualized = true;
return virtualized;
}
// usage...
if(IsVirtualized(WindowsIdentity.GetCurrent().Token))
// better add a manifest to your application if you end here
;-)
Willy.
).