If the programs are actually data files ie.,pictures, text files, etc. you can just cut and paste them from c: to d:. That will move them from c to d. If the files on C are executable files (games and things that were installed and run from START>PROGAMS>finenames) then they need to be uninstalled and reinstalled on drive D. To uninstall, go to Start>Settings>control panel. In the program panel pick 'add/remove programs' and pick the programs to be removed. Tell it to remove each program. Then use the original CD's to reinstall them on D:. That will put them back on the Start>Programs>files. It will look like it did before you moved them except they will be on D: thus giving you the space you wanted on C:
Hope this makes sense to you.
Have a nice day.