Office 2007 Serial virus on t60 == how best to re
 

my t60 (windowsxp pro) has been infected with several viruses.
is it safe to re-install from the windowsxp partition?
or should i kill absolutely everything on the disk (eg. by running killdisk off a cd)?

and if i do the latter,Office 2007 Serial, how on earth to i register it with microsoft because the laptop did not come with any cds.(i can borrow a windows xp pro cd from work - but i presume that there will be problems with the product key and license number etc)any thoughts?