Is this ITK version 5 or version 6? If it is version 5, you should be able to start the install, get the "Wrong OS" message, click ok, then continue. If it is version 6 you should not have this problem.
I just tried the toolkit installer on XP. I got the same obnoxious message box. But when I clicked ok, the dialog went away and the intaller continued. Sometimes the installer window can get hidden behind the big blue window, or even get minimised. Is something like this happening, perhaps?
the installer just hangs when it get to "checking for previous version". i wind up having to exit out by ctl-alt-del. the installer shows up as not responding.
