Cannot Delete Files/Folders "Action Cannot Be Completed.."

Hi,
I have been googling this for days now - trying several different suggestions - but cannot find a fix!

I am in the midst of tranferring data from old computer (Windows Vista) to new computer (Windows 7 Pro) and was placing folders/files on network drive to do so. For 95% of the items, it worked like a charm - I would copy onto my new computer and then delete them from network drive.

However I am left with 5 folders with a few files in each that I cannot delete! Error message is:
The action can't be completed because the file is open in another program. Close the file and try again.

I've tried renaming, Unlocker, stopped windows from caching thumbnails, and a few more than I can't even remember!

I am not a computer whiz by any means and am afraid to attempt anymore on my own in case I mess something up!!

Any help would be appreciated - I am all googled out!!!

Thanks!