Actually Broni had a good idea of creating a new user account. It may clear up the problems and you can use it in place of the other until you get the disks for a repair.
Creating user accounts in Vista is quite simple, once you figure out where to go in the Control Panel. All of the user account tasks are grouped under the User Accounts and Family Safety option in the Control Panel. Once you open this option, the rest of the process is quite similar to that in Windows XP.
The steps for creating a new user account in Vista are outlined below:
1. Click Start and click Control Panel.
2. Click User Accounts and Family Safety.
3. Under User Accounts, click Add or remove user accounts.
4. Click Create a new account.
5. Type in the account name. Select the account type: Standard or Administrator.
6. Click Create Account.
7. Select the account you just created. Click Create a password.
8. Type in a password for the user account and an option password hint.
9. Click Create password.
You will now be able to log on to the computer using the account name and password you specified.
