Tip 1: Use password hint
Password hint does not appear until you input a wrong password. With a password hint, you may guess the password easily or not.

Tip 2: Use password reset disk
Only password reset disk created by that account works, which should be prepared in advance. After inputting a wrong password, click Reset password¡­ under the password box to use Windows password reset disk.

To create a password reset disk:
Before creating Windows 7 password reset disk, you need to log on with the special account you want to create a password reset disk for, and then insert a USB flash drive or floppy disk in your computer. Then follow the steps:
Step 1: Click Start button to select Control Panel.
Step 2: Click on User Accounts and Family Safety, and then click on User Accounts.
Step 3: Click on Create a password reset disk on the left of the following screen.
Step 4: Click Next on the coming wizard and follow its instructions to do the left job.

Tip 3: Use system restore
The preconditions to adopt this method are: you have created a system restore point, and you remember the admin password you used at that time.
1. Press F8 repeatedly as soon as computer starts, then enter Advanced Boot Options.
2. On the Advanced Boot Options screen, use the arrow keys to highlight Repair your computer, and then press Enter.
3. Select a keyboard layout, and then click Next.
4. On the System Recovery Options menu, click System Restore to open it.
5 Check "show more restore points", choose one and then click next.
6 Confirm your restore point and finish, then your computer will be restored to the point you specify.

Tip 4. Use Windows 7 password recovery tools
Windows password breaker is powerful Windows 7 password reset software working under DOS, thus has better compatibility with most computers. It works to reset Windows Local Administrator, Standard and Guest user passwords, and Windows Domain Administrator password in Windows 7/Vista/XP/2000 and Server 2003(R2)/2008(R2).

Start your inaccessible Windows 7 computer with the disk burned by Windows Password Breaker, follow the command and make your selection to execute Windows 7 password recovery in minutes.

Tip 5. Use reinstallation
Actually, with the above four tips in hand, especially the fourth one, there is no need to reinstall. But if you have nothing important on the computer and prefer reinstallation, just go ahead.