Microsoft Games not opening, video not playing, other connected issues

My HDD died, so I opted for a fresh install of Windows 7 Professional on the new HDD. I reinstalled all my programs and drivers and such. But I've had the same problem ever since:

Sometimes, randomly, when I start my computer, these things happen all at once:

• Microsoft Games (solitaire, minesweeper, majong, etc.) will not open. I double-click on them, and then nothing. No error, nothing to indicate the computer is trying to open them. If I go directly to the application and try to open them there, same thing.
• Video does not play correctly. In WMP, it just plays the audio and displays a small screenshot of the video (as if it were album art).
  
  Divx player won't play anything at all. VLC player would open a separate screen called YUV SDL Output. But the latest update for VLC fixed that.
• If I try to play a DVD, I get this error:
  
  • Windows Media Player cannot play DVD video. You might need to adjust your Windows display settings. Open display settings in Control Panel, and then try lowering your screen resolution and color quality settings.
  
  Changing the settings does nothing.
• In Radeon Catalyst Control Center, when I'm adjusting the video settings, I will get an error stating the sample video cannot load.
• If I were to play a game like Portal 2 or Fallout: New Vegas, nothing happens. I put in the disc, and nothing happens. I double-click on the disc, and nothing happens - just as with the Windows Games.

All of these happen at once, randomly, when I start my computer - sometimes everything works fine, sometimes it all stops working. Restarting my laptop usually fixes the problem.

I went through and updated all my drivers, including the graphics drivers and updated Radeon Catalyst Control Center.
I've looked online for solutions but found no problems like mine.

Any help would be much appreciated!

-EDIT-
Another issue that I just remembered:
When on youtube or other streaming media sites (doesn't matter which player is being used) if I try to go fullscreen, it turns the screen black and opens a new tab called Adobe Flash Player. But this "tab" is just transparent and nothing displays. The sound still displays fine though. I also can't do anything. Everywhere I click, it just stops/plays the sound (as if it was in fullscreen). I have to hit Windows+tab or ctrl+alt+delete to get back to regular view.


-EDIT 2-
Found another thing affected. I went to check my Windows Experience Index score and it said there is no information available; you haven't run the test yet. But I have multiple times. So I go to run it and nothing happened. I tried several times but had no response.

I would run the System File Checker 1st. You may have a corrupted install of windows, which will require a reinstall, or at least a repair install.

SFC /SCANNOW Command - System File Checker

Repair Install

A Guy