re-installing home edition

i'm trying to fix my friends laptop at the moment, to put it bluntly a virus
has done more damage than a hammer, the only way of fixing it that i can
think of(and i've tried many things) is a complete re-install of home, he has
the serial, but his comp was shipped from the US with no cd, so i am in
desperate need of either a trial version, which can be activated with serial,
of an cd image i can burn. also i cant email microsoft as i dont have the
PIN, because i cant even start windows!!!!
please help, would be much appreciated.
molome7
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