On Friday early morning last week, I was having a serious problem with my computer. When I got off CSGO, there was a huge update and so I decided to run it. Then it happened. The thing was being absolutely slow and at times, would be unresponsive to any commands I've given to the computer. Even right clicking gave me the little blue circling what-you-mah-call-it. So after my chat with a friend, I closed my computer to get on it the next day.

The next day, things really went down hill. I went to check on my FB and the computer suddenly froze due to unresponsiveness. Waited...waited, lost my patience and shut my computer off via power button. So I tried again and went on steam, slower than usual. Tried to update CSGO and after I let it go, it restarted on its own after a few minutes. When it was booting up, it all went black then gave me the following message "BOOT MGR missing. Press CTRL + Alt + Delete" to restart. So I did and it still gave me the same thing. So I pressed the button once again and then it gave me the option to go into safe mode or normally start it. [Normal started].

I thought my drivers went crappy, so I downloaded the drivers. Now, I'm not sure if its acceptable but I installed the newest drivers over my current drivers. Damn computer went non-responsive multiple times during the installation then it gave me a warning. "Installation Failed. 'view details here'" So I did and it gave me a list, and also my display drivers wouldn't install.
So, I went the the defragging. I've been defragging this computer since Friday night and I've seen over 1,750 fragmented files listed in my defraggler. So I ran it and I'm still seeing so many red blocks. This took 3 days. Even now, after I defragged every directory, it still has non-responsiveness. Even though my AMD had the most problems. I don't know.
I have many theories but to put it straight, I'm a dummy at computer stuff and you know I'm afraid to touch the sensitive stuff. I took a guess it would be my RAM clocking, but I don't think it is. My specs are as shown below:

Operating System: Windows 7 Home Premium 64-bit SP1
CPU: Intel Core i3 540 @ 3.07GHz (average temperature at 26C)
RAM: 8.00GB Dual Channel DDR3 @ 664 MHz (9-9-9-24 clocking)
Motherboard: Intel Corporation DH55HC (XU1) [Avg. temp. 35C]
Graphics: SyncMaster P2050 (1600x900@60Hz)
1024MB ATI Radeon HD 6700 Series (AIT AIB)
Optical Drives: ATAPI iHAS524 B ATA Device
Note: Do clarify if this is bad. Any help you offer me will be so much appreciated.
Bus Speed: 133.0MHz
Rated Bus Speed: 2926.3MHz
Stock Core Speed: 3066MHz
Stock Bus Speed: 133MHz
Physical Memory Usage: 21%. I've NEVER seen it used in the 2-3 years I've owned this computer.