How do I change windows seven basic theme back to windows seven aero?

I was downloaded a program, and suddenly, in the corner of my task bar, it tells me: Your windows 7 theme has been changed to windows 7 basic (or something similar to that.) I've tried everything, looking through other threads and trying tutorials from other people. I can't seem to change it back to windows aero theme. Are there any solutions to change it without damaging my computer? Also, I wasn't running any programs at that time besides Skype. This has never happened to me before, and I just want to change it back.

Screenshots:

When I try to change the windows color:


What I see with themes (no aero theme):

Brink said:

Hello Jenny, and welcome to Seven Forums.

Double check the items below to see if any of them may be a cause. :)

• Aero Requirements to be Enabled in Windows 7
• You ust be have True Color (32 bit) set instead of High Color (16 bit).
• Be sure to have the correct Windows 7 driver version installed for your graphics card/chip.
• The desktop composition and Animate controls and elements inside windows options enabled in Visual Effects.
• Refresh or update your WEI score.
• The Desktop Window Manager Session Manager and Themes Services need to be set to Start and Automatic.

Hope this helps,
Shawn

Thank you so much. You were GREAT help! You did an incredible job helping me solve my solution. (: