In case you forget your password, you can create a password recovery floppy disk beforehand to help you out of this problem.
1. Single-click Start menu
2. Go to the Control Panel / User Accounts
3. Click the User Account
4. On the left hand side, click on Prevent forgotten password
5. You will need to know your password to create the disk.
6. If you don't remember your password sometime in the future, click on the green arrow like normal at the login and you will be prompted to insert the password recover disk.