Hi there my laptop's keyboard doesn't work in a windows application but does work startup bios, al the keys work there but once in windows there is no hope, when I plug in an external keyboard it works again, what should I do?

Couple of ideas here:

https://www.askmehelpdesk.com/other-computers/keyboard-locked-130874.html

Make sure Filter Keys is off (go to Control Panel. Click on "Accessibility Options"). Make sure nothing is checked on the Keyboard tab.