I just played around with Thandor trying to install it and see what the differences are between Win98 and Wine because I noticed a slightly different behaviour. Now I discovered that MoveFileEx is not even available in Windows 98 but wine supplies it nevertheless. I suspect that the Setup doesn't check the windows version, but rather calls MoveFileEx and if that fails with not implemented returncode continues with other code to supply the functionality. I wrote a small test app to confirm this and this returns an error code when calling MoveFileEx on a native win98 whiel wine executes it.
How shall I fix this? Shall I simply call GetVersion() to determine if MoveFileEx should be allowed or is there a different way with wine to determine which functions are available for which version (a global variable or such)? I looked through the sources but I couldn't find anywhere something where a versioncheck has been used to switch code but then again I don't know much functions where I know for sure that they are available in one version and not in the other.