My C drive is about filled 3/4 of the way and my D drive is basically empty. Could I put some files from the C drive to the D drive? or does the D drive not work like that?
Software - That will be hard and probably requires a reinstall of said software
Data (Images, Movies, Music etc) - Probably no problem. If you're using a media player like Winamp or Windows shit you gotta redirect the media library.
My C drive is about filled 3/4 of the way and my D drive is basically empty. Could I put some files from the C drive to the D drive? or does the D drive not work like that?
Recording projects and sample libraries should be on your D drive.
You can move your "My Music" and "My Videos" folders to the D drive which should save give you a lot more space on the C drive.
Since you don't seem to know much about computers you've probably never done anything to maintain the system. Get Crap Cleaner and Defraggler
Run CCleaner weekly.
Run Defraggler monthly for each drive. http://www.piriform.com/