Wrong, wrong, wrong. Reinstalling Windows it the last thing you want to do.
There are two password possibilities, and you haven't said which one is needed. The first is a BIOS power-on password that pops up when you first turn on the power. If you don't know that one, you cannot even get to a Windows login screen. You can (usually) briefly remove the button-cell "coin" battery on the motherboard to erase that one (as long as it's in a plastic carrier and not soldered in). Lucky you have a desktop -- some laptops can be very difficult. Reinstalling Windows will be impossible if you cannot get past this password.
If you've forgotten your Windows login password, and have another account that has Admin authority, login to the second account and change or delete it in User Settings.
If you forgot your Windows password and you have other Limited accounts, use one of them to do a Google search to download software to delete the forgotten password. Some of them involve running Linux from a CD you've created and using Linux commands. Again, Google search. And next time, don't get so clever with passwords. 9 is a perfectly good Windows password. You could add Admin or Limited accounts anyway so someone else can use your PC, and those won't necessarily need a password.
If you have only one account, you'll need to download and burn a Linux CD or a USB drive boot/password tool on another PC. Or call Best Buy GeekSquad or similar and find out how much they charge, since they already have the tools (online vendors used to charge $500 for various password unlock tools; today they're free).