You need one of five things:
1. A Windows install Disc (ie Windows Xp CD)
2. A Restore Disc (Many companies now use Restore discs - this disc is intended to Restore Windows + drivers + applications)
3. A Restore partition (Many computers sold now, have Windows restore partition actually on your Hard Drive. Usually accessible by hitting a specific key upon your computer startup).
4. Contact your computers manufacture to get a Restore disc
5. Buy a Windows CD !
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