My PC keyboard plugs into a USB port, and the keys do not work until after Windows boots up. How do I enter Bios or Safe Mode during a system boot?
You do not have to get a non-USB keyboard to have access to keyboard functions during boot. What is likely happening is that an option in your BIOS called ‘USB keyboard support’ is disabled or turned off. If this is the case, support of the keyboard is left up to the OS, in your case – Windows. If you enable ‘USB keyboard support’ in your BIOS, the BIOS will respond to keyboard input. There is a downside though – BIOS support of a keyboard is basic and may not include any support for any ‘special’ keys like on many multimedia keyboards. The previous person has a point though – to access the BIOS and make this change, you’ll need a non-USB keyboard to make the change. This is not the only possible cause of your issue, but it’s the one that jumped up at me.
