mcafee updates backup....can't view div2 video.....streaming video is restarting my PC

i want to back up my updates for mcafee antivirus...i'm gonna restore my Pc and since i have dial-up i don't want to dl the whole crap...can i back up the current updates from a file to a cd-rw?.........

i dl'd a video and when i try to see it wmp won't play...it says error dl'ing codec....when i tried opening it with virtualdub to try to save it as avi...it says that it cannot read format 'div2'.....i am assuming it is a divx codec, but i have the current divx player.....what can i do?

when i try to view streaming video from the net...it reboots my pc...why?.....i first experienced it on launch.yahoo....but when i tried to see something from the velvetrevolver website..it did the same thing....it's really annoying and i am very curious to know what the problem is......

thanx in advance for all the help