I've seen that happen for a few reasons.
1. The owner installed some USB or motherboard drivers and we had to go to SAFE MODE to rollback the drivers. I'll not write how since after a decade it's on the web.
2. The owner installed that horrible Logitech driver and for removal, it's a pain.
3. The BIOS needs to be set for or unset in Legacy Keyboard. As I can't find the make and model I'll stop here.
Bob
I can't get my computer to recognize my keyboard
The motherboard sees it, I can use the keyboard after entering setup.
I haven't used this computer for about a week. Upon power up everything sounded normal until I tried to use the keyboard.
It won't work with XP

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic