There seems to be a conflict between Windows 2000 using DirectX 9.0b or Windows XP running service pack 2, and Petz 5. There are 2 files that gets installed into the Petz folder called 'setupapi.dll' and 'smapi.dll' that appears to be causing a conflict with other newer system files installed with the latest Windows service packs. The workaround is to delete these files (setupapi.dll and smapi.dll) from the main Petz folder and try running the game again.