After you install QuickBooks, you may be asked to register. If you forgot your registration credentials but you have your validation code, you can validate QuickBooks quickly and easily.
1. Open QuickBooks but do not open the company file just yet. If you already have QuickBooks open, select file> close company.
2. Go to help > about QuickBooks.
3. When the green box with the registration information appears, press CTRL+R+P.
4. Enter your validation code.
5. Click next to finish.