First question: Do you mean you would like to use your existing XP by duping it onto the current D drive? If so I would suggest that it appears you have plenty of space still on C so first copy all the data off D onto a new folder on C (assuming C has enough space available to do this). Then using something like Norton Ghost and possibly some of the hard drive manufacturers utility programs, dupe the C drive onto D. You need to do this as a dupe and not just a file copy, otherwise it will not work. If you don't have enough room on the current C for all the data, you will need to copy the data somewhere else in the interim, another drive would be best. I have done it with Ghost just fine, I am uncertain the hard drive utility programs will do it with XP but they might.