How do take my Dell laptop back to its original condition from when I first got it?

I bought a Dell Inspirion laptop in January 2009. A lot of things have been added/downloaded onto it. I have had virus', it runs slow, freeze and no room to do anything else. I want to take it back to its original condition/ configuration from when I first took it out of the box. How do I do this?|||There should be a factory restore partition on your hard drive, assuming you never wiped it. It's probably under D:\. Look in there. If you can't figure it out where the program is there to restore things, call Dell Tech Support, assuming you want to pay them for it.|||Some Dell's come with a special boot section. You need to press a key combination on boot to access it. Either that, or you should have bought the restore media.