This is the weirdest issue I have experienced with Windows before, I have absolutely no clue what is going on.
I can write small and large files to my external drives, and i can read small files, but I cant read large files, or copy them back to my desktop
Usually I can read any file under 100-200MB, anything larger and windows explorer locks up, or the program (e.g. VLC player) will crash.
When copying to the desktop, the transfer indicator will freeze half-way (at around 200-300mb) always... I cant close the explorer window, I have to pull out my external HDD usb cable..
This has occured with my Iomega External Drive, although my other External Drive (WD MyBook 1TB) has done it a few times as well, but its noway near as bad as the Iomega drive. And only on this computer (Windows 7 64-bit).
I have ran windows updates and installed all of them, I have updated my intel chipset drivers
and flashed / updated my BIOS all to the latest.