If you lose or forget your Windows 7 login password, you can use a password reset disc to create a new one.
Create a password reset disc
Creating a password reset disc is one of the first things you should do once you’ve first set up your computer or installed Windows 7. Should you forget the administrator password it means you can reset it quickly without having to reinstall the full operating system again.
Step 1 Insert the blank disc that you wish to use as the password reset disc. It can be a CD-Rom or a USB flash drive, for example.
Step 2 Click Start, then click Control Panel.
Step 3 Click User Accounts and Family Safety and then click User Accounts.
Step 4 Click Create a password reset disc in the left-hand panel, and follow the onscreen instructions.
Step 5 Keep the disc in a safe place once done.