Sort of a dodgy request

ok so heres the deal
keep it on the d.l.e.l. hehe

so i obtained a copy of max 4 from my friend - very legal stuff here -
i installed it an it worked fine, this was when i had win98

so, i install the upgrade to winXP and bam i get these message now:

the os has changed please reinstall the program (impossible for me to do as i neglected to make a copy of the cd…doh)

and

a license error has occured, please restart your system blah blah blah

ok, im out of touch with this friend right now so does anyone know a way around this??

PLEASE HELP without my max im lost…where am i???
thx