Hello lilleydon.
Check the Dell's documentation for your PC: it's a common practice for computers' manufacturers to set up a recovery partition and a set of recovery tools that can be activated to perform a full system restore by pressing some keys; only the computer's documentation
can tell you what you have to do.
If your PC does not have a recovery partition, you have to contact Dell and ask for a set of recovery discs.
Bye.
Luigi Bruno