NS7.2 won't launch after install of XP Pro

OK.. just did a clean install in xp pro on one of my users pc's... loaded xp and everything fine... installed some programs.. FF, MS Office etc... no problems.. went to install NS 7.2 and everything went as planned... BUT NS 7.2 will not launch.. used both the little installer and the full install... get no errors or anything, but click on NS7.2 and it will not open.
Tried uninstalling and reinstalling with no luck
Any ideas?
TIA