Well....first off, you can't move free space. The space on a drive is..... the space (capacity) on a drive. It cannot be swapped or moved to another drive....i.e. move 20 gigs of "free space" from a 30 gig drive over to a 20 gig drive and make it now 50 gigs. It would be nice, but it doesn't work that way.

What you can do is free up space on a drive; either by deleting old files, uninstalling uneeded programs/old games, etc..

If you desire, you can unistall games/programs off of the C drive, then reinstall them onto the D Drive....but bear in mind that some programs/games will still install a few files to the C Drive because they are just coded that way. You can also move documents and other data over to new folders created on the D drive. All this could give you some extra room on that C Drive.

The BEST solution though would be to just simply replace those old drives with drives of a higher capacity....both of those drives are pretty long in the tooth.....like me.