What happens

[BackBreaker]

if you put in wrong ram accidentally and totally replace your working ram does the computer mess up, fry, or just not turn on or what? Like lets say your computer only supports 533 mgh ram and you put 800 mgh ram in that doesnt have other speed sit works in.

[18 is # 1]

If you are putting DDR2 in a DDR2 machine, it will downclock to the speed of the machine. DDR1 won't work/post at all.