How to system restore my dell

Ok i have a dell dimension 2400 and its been really slow lately and virus scans and stuff dont work so i was thinking of doing a system restore. However i dont have any cds. Sooo i was wondering what cds i would need and where i could download them. Also if i need anything else tell me where i can get it please. =)

Dell has a built in destructive restore function which came out sometime in 05. To use this do the following.
Restart your Dell.

After the Dell logo fades, you will see a blue bar at the top of the screen with "www.dell.com" in it. The blue bar is displayed for exactly two seconds.

As soon as you see that blue bar, press the Control and F11 keys at the same time, hold for a half second, then release.

This will bring up "Dell PC Restore" by Symantec. Follow the prompts to run the recovery procedure. Takes less than 15 minutes.

Be advised that running this recovery procedure deletes all user information on the hard disk drive, and recovers the c: partition of the hard disk back to the exact condition it was in when you first got the computer brand new from Dell. So before running it, be sure to offload anything you want to save.

This is perfect for your situation. Sure, the National Security Agency could still analyze the hard disk and get your secret chocolate chip cookie recipe, but average folks won't be able to recover any personal information. Be advised that whomever buys it will need to do all microsoft updates starting from the time the puter was orig. bought until now.

well im not sure if my dell has that feature because i dont see the blue bar and i tried pressing control f11 after the dell logo faded but before the windows xp thing came up and nothing happened. Is there another way to access this feature?

ok thx again for the help ill try this tomorrow hopefully it works