does your comp have a recovery partition? if yes. see if this helps. http://www.techsupportforum.com/hardware-s...structions.html
if no. put the disc in drive and restart. you may have to enable boot from cd drive 1st.
to enter bios restart. start tapping the f2 key. you will enter bios screen.
enter bios and choose cd/dvd drive to be 1st to boot. using arrow keys. when you have cd set 1st hit the f10 key to save settings and exit.
restart then recover disc will boot. follow instructions. (restore to factory condition or something like that.you will lose all your data. ie pictures ect