HISTORY:
My old PC had a 160 GB HD, later i bought a new 1TB HD. SInce my old PC had a lesser power PSU/SMPS, it couldn't handle both HDs together and often caused my PC to freeze/hang. So i removed the 1TB HD and kept it away as i was gonna change my whole internal system including - Motherboard, Processor, RAM and SMPS/PSU; excluding my internal Hard Disks.

PROBLEM:
Now i have a 500W PSU for AMD FX-6300 CPU, 4GB DDR3 RAM and the cheapest video card ever along with my 2 HDS (160 GB and 1 TB), which is supposed to be sufficient as i don't have a high end config.
Ever since I got my system renewed, the copy/move process of large files (around greater 500 MB) to the 1TB internal HD gets stuck at like 30-40%. The copy/move speed falls to 0 kb/s and once a while moves to 2 or 3 kb/s, but with no progress whatsoever. When I checked the performance tab in task manager, the 1 TB HD shows 0% active time, avg response time 0 ms. When this happens, the copy/move process doesn't get cancelled and windows operates extremely slow; the only solution is by cold restarting the pc with the tiny button.

FACTS:

The 1TB drive operates perfectly for all other processes; no problems copying/moving files "from the drive". No wierd sounds coming from it, and i can play and run files stored in it with no problems.

PLEASE HELP