Question: On OS from win 2000 or later (any language) can I assume that this path will always exists?
For example I know that on win xp in some languages the "Program Files" directory have a different name.
So is it true for the System32 folder?

Thanks.
Ohad.

Answer: 
Windows can be installed on a different harddrive and or in a different folder. Use the %windir% or %systemroot% environment variables to get you to the windows folder and append system32. Or use the %path% variable, it's usually the first entrance and the preferred method of searching for files such as dlls AFAIK. As per comments: don't rely too much on the system32 dir being the first item. I do think it's safe to assume it's in %path% somewhere though.
Just an FYI, but in a Terminal Server environment (ie, Citrix), GetWindowsDirectory() may return a unique path for a remote user. 

[link text](http://msdn.microsoft.com/en-us/library/ms724454(VS.85).aspx)

As more and more companies use virtualized desktops, developers need to keep this in mind.