GROD In Only One Folder, Can't Delete/move/rename Files In It

I have a acer aspire 7750G-6634 laptop, 8gb of ram, 2 HDs, i5, windows 7 home (the one that came with the laptop)?Camtasia created a 50+ gb file on my D drive, I struggled to get the file to work but it seems like it was corrupted (couldn't use it) so I deleted it. Since then I started seeing the green ribbon of death when I was browsing folders on my D. It was always getting worse and worse, until one day I couldn't move/copy/delete any files that was on my D. Then I rebooted and my D drive disappeared?I was able to remove it, 30 minutes in the freezer, then I was able to connect it and save some files (maybe 75% of the files), then can't access it anymore.I bought a new HD from newegg (Seagate Momentus ST9750420AS 750GB 7200 RPM 16MB Cache 2.5" SATA 3.0Gb/s Internal Notebook Hard Drive -Bare Drive - OEM) and put the new one to replace the one that died.So far so good, but now I see that green ribbon again, but only on my D and only in my "Downloads" folder, the other folders on the D seems to be fine. I can't delete or modify any files in the Download folder.

*Scanned with Superantispyware
*Scanned with AVG2012
*Replaced AVG2012 with AVAST (Had issue with AVG before and I read it could be the cause of the issue)
*Scanned with Avast
*Scanned with SlimDrivers and updated the 15 drivers that were out of date
*Scanned with Emergency Kit (scan never finishes scanning, get stuck at 97% on 3 different files on the D drive so far)
*Checkdisk on both drives (C and D) 3 times (when booting the PC) 4-5 hours each time
*Defraged both disks
*Uninstalled Camtasia + many other softwares that I installed when the issue started (approx.)
*Used CCleaner and cleaned the registry and other files
*Tried to use Xplorer2 instead of windows explorer = same issue