How do I delete an existing user account in Vista?
1. Click on Start and choose Control Panel
2. In the Control Panel, select User Accounts
3. Under the make changes to your user account, select Manage another account
4. Select the account you wish to delete.
5. At the make changes to account screen, choose "delete the account"
6. Determine whether you want to keep or delete the files associated by the account.
7. The account is now deleted.
You may not delete an account if you are currently logged in as that user.
A standard user may not delete an administrator account.
The sole administrator account may not be deleted until another is created.