Dell XPS 400 usb port not work

[Adriel]

Dell XPS 400 usb port problem . Keyboard and mouse are not functioning as I get a keyboard failure. I installed an USB Port into the expansion slot and now the keyboard and mouse work only after the OS starts up. when my computer starts it says Keyboard and mouse failure then begins to run.

Can some one help me ?

Thanks

[KADEN]

Check in the BIOS for an Enalble Legacy mouse/kdb support and make sure it is enabled. Is USB mouse/keyboard plugged "directly" into the PC and not through a hub ?

[Caesar]

Confirm the USB is not working in Safe Mode either. To get to Safe Mode, repeatively press F8 key before Windows startup. Run a Dell iagnostics Hardware test on all your hardware.