If your Visual C++ 6.0 often fails (hangs) when building projects on Windows XP, it's not your fault. It might be the user environment variable TMP that causes trouble. Try to modify your TMP to a shorter path, for example, c:\windows\temp (the same as system environment variable TMP).
The similar problem happens when some Windows XP users cannot create new e-mails by Lotus Notes. It can be fixed by the same way.

List of bugs that are fixed in Visual Studio 6.0 Service Pack 6
KB327146 - FIX: VCSpawn Fails During Build