windows startup freezing after uninstall of nis 2010

Hi, I bought a retail boxed version on nis 2011 and when I ran it it started to uninstall nis 2010 and when it came to reboot my windows xp wouldn't start up in normal or safe mode or at last good settings, when I put the xp disk in to try to repair it freezes at setup is starting windows, any help anybody....regards