How do you lock the Fn-key on keyboard?

Sometimes my keyboard on my compaq cq61 writes in caps when caps lock is off when i turn it on writes in small?

• at the same time numbers will not work on right hand side off keyboard with num lock on or off also if i use the numbers above say i press 5 i get % or 8 i get * this is every number not its come to the stage that nothing works on the keyboard other than ctrl enter and backspace when i try to do ctrl +c to copy with the left ctrl button doesn't work tho the right hand side one works ive cleaned the keyboard nothing has been split in it, everything was fine i just came on one day and it started to play up about 2 days ago the weird thing is it only happens now and again and stays like this for maybe 30 seconds to 1 minute CAN SOMEONE PLEASE TRY AND HELP ME OUT thanks

• Answer:

  I have this problem with my Compaq at times. There isn't really any way to fix it permanently but I have found pressing the caps lock key a couple of times when this happens fixes it for me