WINDOWS XP DISAPPEARED AFTER SYSTEM RESTORE

Hi Sorry to ask what is probably a really basic question, but recently my pc
had a major error occur and I had to run a system restore - this removed all
my files which I managed to restore, but it has removed all Windows XP /
Office items (i.e. Word, Spread*** etc). When I have tried to reinstall
itunes and MSN Messenger cannot do so as it keeps coming up with a message
saying i do not have Windows XP installed. I cannot locate the original disc
to reinstall XP - does anyone have any advice. Thanks very much.
Regards, Amanda
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