Cougar, we have a 404 repeat 404!
(sorry, just worked for my tired brain)
Phil, I know this from buggering about with computers a lot, no idea how I knew this particular info but it was a recent thing…
You basically need to download http://msft.digitalrivercontent.net/win/X17-24209.iso , mnake sure the file described in the first link I sent is appropriately edited then burn the ISO to a disk or USB stick with an appropriate program. If you’re not confident with this step, as I said, I can burn you a disk but you’ll need to wait.
You then open the BIOS when you start your laptop (DEL/F2/F1 will usually do it), go to disk management and then make sure that the optical drive or removable media (depending on which you are using) are a higher priority than the HDD. Save and exit and you’ll be good to go.
The disk/USB should then boot up and you’ll be given the option to install the version you need. You’ll have to input the serial number and once it’s all installed go to the Dell site and download teh loatest software and drivers if you feel the need (though to be honest I doubt you’ll need any of that crap as 7 is clever enough to install appropriate drivers anyway).