First stop would probably be Dell, and finding out whether or not they still have copies of the restore media. They might charge you a small fee, but it'd probably be cheaper than finding an OEM copy of Vista on eBay or some such, and going that route.
After many years of using this PC it's in definate need of a full restart, however I lost the Vista disks in a house move a long time ago..
How would I go about putting it back to factory settings basicly so I can start again on a blank slate, but still with vista.
Thanks so much for any help.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic