I've got a Dell Win7 64 CD / ISO I could get you, doesn't have all the crapware installed by default either - it's just a vanilla Dell Win7 CD. Just backup your shizzle to a USB drive, reinstall et voila done. Better than having someone getting your private info/bank details/porn
The CD key in the machine will be Dell's factory one and after a few months may want it's own putting in, you should have one under the laptop, or under the battery as it's a Dell. I use ProduKey from Nirsoft for extracting Windows/Office Keys.