Notebook Boot and Lockup

Windows 7, plenty of hdd, plenty of RAM, blah,blah,blah.

Laptop worked great for the first 6 months. Suddenly one day, it took a very long time to boot. Once booted, programs would take a very long time to load. Clicking on anything would cause the computer to freeze up. Simply clicking start would take a good three minutes for the start menu to pop up. I thought maybe I had a virus or some malware, so I wiped the hard drive and started over from recovery. with a fresh recovery, everything seemed to work as normal again... for about three or four boots. Then right back the same old locking up slowed down behavior.

I have done the recovery five or six times now, and every time that works for a few boots, but then goes right back the same behavior.

As of right now, there is nothing on the laptop; it is a fresh install. Still, I get the same behavior. I have checked task manager and there're very few applications running when this happens. The CPU and memory usage are always very low, with the CPU usage usually being below 10% and the memory usage usually less than one third of total.

I thought maybe the hard drive was corrupted so I tried replacing it. However I cannot seem to get the recovery disk to reinstall Windows 7 on the new hard drive. I'm not so sure that there is anything wrong with the old hard drive. I have run check disk and defragment several times with no issues.

I just tried to use a laptop to do some homework and it was freezing up again so I tried to shut it down. I left it sit for three hours on the logging off screen and it still did not shut down.

I'm lost. I can't seem to find anything on Google about this kind of issue. Any ideas?
Thanks in advance!