AFAIK, "c:foo" is NOT a valid Win32 pathname. Well, it is an odd pathname, anyway. Using the command prompt on Win2K, with the current working directory set to "C:\", I can invoke "cd c:foo", which will change the CWD to C:\foo.
Issuing the exact same command will cause a "cannot find path" error. Even better, if I invoke the same command while in C:\Program Files, it will try to put me in C:\Program Files\foo. Very odd.
Anyway, how do I verify that a path from SdAskDestPath() is any good?