??

Hi I ahve an ? i am not sure what it is related to but it seems when i boot my system maybe after 20 mins or so the three lights the caps lock and the other two start blinking and my system locks up the only thing i found was that my monitor cable into the computer was somewhat loose and i am not sure if that would all of an sudden do it after so long on any one have any ideas what else might make these lights blink and lock the machine yp thanks in advance Bob