Maybe you accidentally changed your keyboard layout. I onced loanedHP Pavilion G60 laptop
Vista Home Premium
Out of nowhere, my keyboard has literally gone crazy. Almost
every key stroke results in either a different letter, or a random
series of letters/numbers/actions. I actually had to connect an
external USB keyboard just to enter the sfc /scannow command (the
Enter key was whacked out, too). Finally, I just gave up and did a
System Recovery. When it finished, amazingly the problem was
still NOT solved.
my laptop to a friend and he changed it to use Dvorak. I had to
change it back to QUERTY.