roy69

List your system specs. How old is your system. Or tell us the model number of your Dell and we will try to advise. By the sound of your harddrive size you may need to upgrade parts of your computer. One option you may have is to get a harddrive and install vista on it to see how it goes. If you have alot of problems then you can always revert back.
If you need to reformat and reinstall you may need to phone microsoft but this is easy to achive and when you need to do it there is a tutorial on this web site on how it is done.