If QuickBooks won't open on your computer, there are a few things you can try. Firstly, check that your computer meets the system requirements for the version of QuickBooks you're using. You can also try restarting your computer or running QuickBooks as an administrator. If these steps don't work, you may need to repair or reinstall QuickBooks. Additionally, it's always a good idea to back up your company file before making any changes to your software.