Yes it's pretty simple.
Put in your Operating System CD, then reboot your computer. Go into your BIOS by pressing DEL, or F2 or whatever it tells you to 'Enter Setup'. Then make sure that your CD-rom is the first enabled boot device. Exit BIOS and follow the directions shown on your screen and all should be well. If you need more of a help than this just ask and maybe we can try to find you some graphical pictures showing it.
Also what OS are you trying to re-install?
BTW :wave:Welcome to TechSpot:wave: