Posted 15 June 2012 - 08:38 AM
The first thing I would try is if you have the repair cd:
Put your windows 7 operating system CD into your CD-Rom drive and start your computer.
Choose the specified key to run from the CD. In most cases, a message will appear which instructs you to "Press any key to boot from CD."
Wait for Setup to check your system and load the appropriate files. A message will appear indicating this action.
Press "Enter" to setup Windows. Press F8 to accept the Licensing Agreement, then choose the "Repair" option on the Setup screen.
Allow the Repair function to complete its process. It may takes a few minutes for Setup to copy all of your files. Wait for the computer to reboot. Usually a message appears indicating that the computer will reboot in 10 to 15 seconds. Refrain from pressing any keys after the computer starts again. The computer will reboot automatically.
Watch the bottom left corner of your screen for the "Installing Devices" message. Press "Shift + F10" when you see this. A command console will appear allowing for access to a number of system functions.
Type "NUSRMGR.CPL" and press "Enter" after the prompt. This will give you graphical access to the User Accounts in your Control Panel.
Select the account that needs to be changed and alter your password or remove it altogether. Type "control userpasswords2" if you want to log on without using a password. Close the windows and exit the command console. Enter your Product ID when prompted.
Log on to your system according to the new password option you chose in Step 8. This process does not damage your previously saved files and settings, so they should still be intact.
If you don't have a cd you can easily download one, if you think this is too much trouble my next advice is to reinstall windows, if you have important files you need to retrieve, then get a live linux co such as knoppix or any other will do, boot up and stick you usb thumb drive and retrieve you important data.
You can also use a windows recovery tool.
This things happen, there is a great feature and I suggest you take advantage of it, is to add a hint to your password something that will help you remember your password in occasions like this one.