Question USB keyboard and mouse only works in BIOS ?

Apr 9, 2021
I have an old pc which hasn't been used in years and contains files that I presently need. When I turned it on, the "chassis has been opened" warning popped up, but it gave an option to press F1 to continue, so I did, but once the login screen loaded, both my keyboard and mouse no longer works. The mouse's light was on right up to this point too, and then it went out. So I switched off my pc using the power button, turned it on again, and same thing happened with the chassis warning. This time I accessed BIOS. Not very techy though so I'm not really sure what I was supposed to do there either, just wanted to check if my keyboard works, and it did. But when I loaded the login screen it stopped working again.

Im hesitant to pay to fix this pc because I haven't used it in years and I only need to fetch some files from it this once. After this I know I won't be using it anymore. Is there anything I can do to fix this issue myself?

If it matters any, it's an acer pc running on windows 7
hi, if keyboard/mouse works in bios while in OS they dont...well ure missing drivers
since its a PC which u wont be using anymore...easiest way would be using some live CD operating system just to fetch files
u can use hiren boot which contains windows 10PE x64 on it
u can burn it on dvd or use usb thumb drive, then boot from it