I followed a similar routue following a hardware problem - reinstalled Windows XP Pro and all software - including Poser 4 and 5. Then took the plunge and installed XP SP2 and to my surprise (after reading all the negative stuff) all my software worked ok including broadband access to the internet. The only follow up work was to adjust a few settings in the new Security Centre so the the windows firewall was turned off in favour of my own. Anyway, if you did have problems then I understand you can reverse the installation of SP2 anyway.