Another hint:
A friend of mine bought a Dell Notebook with WinME OEM preinstalled and asked me to switch her system to W2K (she didn\'t know how to do it she\'s merely using it, doesn\'t know much about technical issues of OSs and how to install them etc.)
Though upgrading to W2K from ME is not quite clean (from my experience) we still decided to upgrade coz she already had some software installed, but W2K didn\'t let me upgrade, i guess it was just simply because of the OEM version (which was branded by Dell). So we took the step and made backups and i did a fresh install of W2K.
I guess it\'ll be the same with WinXP OEM. Maybe some tools that \"de-brand\" Windoze would help out (e.g. X-Setup by X-Teq), but i guess it\'s rather related to the serial number which marks your WinXP version as OEM, so i\'d say there\'s no chance.
