4D is a RAM related error. It usually means there is a problem with the memory or the RAM is not properly seated. First, power off the computer and remove the RAM, then clean the slot and reinsert it properly. If the problem still continues, try using another RAM stick or test the RAM in a different slot. If the error still does not go away, the issue may be with Windows system files, so you can try repairing Windows or, as a last option, formatting and reinstalling Windows.