Manually close used files and retry the operation?

Hello,
I have Paragon Disk Wiper 8.5 Professional. I just want to wipe "clear the free space" from my D: drive which has Windows XP on it as well as the Disk Wiper program. C: drive has Windows 98 on it and is not involved. Wipe Wizard goes through its sequences and I finish/close the wizard. Then I click "apply pending changes" and a window pops up and says "Operation "extended wipe partition or disk" cannot be completed because Volume D: is being used now. Please try the following, Manually close used files and retry the operation".
Do I need to run Disk Wiper from C: drive to work on D: drive? Or do I need to run the Wiping Media Builder Disk from my CD drive?
All I want to do is destroy already shredded and deleted files I have done with other programs (Eraser) but the file names still exist on the deleted files when I use PC Inspector to view them.
Any help on the correct way to accomplish my task would be appreciated. I hope that Disk Wiper will do what I want; scan the file table for previously deleted files and wipe out the file names of deleted entries?

Any help would be appreciated,
Jonday