said by BigBlarg:
I never cleaned my registers
It's important. The CPU has several registers, and when you shut down the computer, they are left containing whatever crap was last there.
You should always run a program to zero out all registers after system shutdown, otherwise it's harder for the CPU to write new values into them.
It's the same principle as erasing a blackboard now and then. Or at least, I think it is.
The same is true of RAM. It takes more effort to write on top of words that aren't zero; the computer has to press harder on the RAM chips.