mouse & keyboard not workin after failed service pack 2 update

Hi,
I tried to install Service Pack 2 on my home computer, however during
installation my computer crashed and restarted. When it booted back up i got
a message saying that things are unstable and that i should go into control
panel and remove service pack 2 (add/remove programs). i did this as it said
but once it had done and told me i needed to retart my mouse and keyboard
stopped working. I restarted by hitting the restart button on my computer
however the mouse and keyboard still dont work. I use a wireless mouse and
keyboard. The keyboard works on bootup as i can get into System Config by
hitting F2 so its not the connection. Its just wen windows loads up and I
have to select a profile it doesnt work anymore! please help Thanks