Being that you have a dell laptop, getting a clean os is fairly easy. I bought a vostro 1520 not too long ago, and Dell gives you an OS reinstall disk, a driver disk, and any disks for software pre-installed (for me it was a cd burning software).
Just take the reinstall disc, and put it in the machine, and reinstall windows with that disc. You will have a clean OS. Afterwards, stick in your driver disc, and it will ask you if you want to run a special program that will read your system to find out all the hardware on it, and then it will give you a list of the drivers for your laptop with a check mark next to the items that it found on your system.
Once you are done installing the drivers, you can enjoy your new Dell computer without all the crapware.