Procedure: Restoring Dell 1501 to Factory Settings

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Assumptions:
1. You still have Vista and the Recovery Partition intact.
2. You have backed up all important data

Procedure:
1. Press "F8" on bootup to access "Advance Boot Option"
2. Choose "Repair your computer"
3. Specify language; click Next.
4. Log in; click OK.
5. Click Dell Factory Image Restore.
6. In the Dell Factory Image Restore window, click Next.
7. Check on: reformat hard drive and restore system software to factory condition.
8. Click Next. The computer is restored to the default factory configuration.
9. When the restore operation is completed, click Finish to restart the computer."

source: http://answers.yahoo.com/question/index?qid=20080917173128AAitMIh
tried and tested
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