Windows 7: How to change Classic theme to 7 theme?

I want to change my theme, but I can't. In Personalization every Aero themes and installed themes go darker and can't use them as my current theme.
So I just want to know how to solve this problems. Thanks in advance.

could you post a screen shot of how your desktop looks now?

http://www.**************/imgbnc.php/...cd0d6fde6g.jpg
Here it is.

oops.
start with a SFC /SCANNOW Command - System File Checker

sfc /scannow doesn't find any problems.

try a System Restore before the problem happened

Type "services.msc" in a Run Box (Windows Key + R) or a Search Box from the Start Menu (if you disabled Search, go to Control Panel - Programs and Features, Turn Windows Features on or Off, find Windows Search, select it. Then press OK.

After, go down to Themes, Right Click, select Properties. Change the Startup Type to Automatic and press OK. Then on the left click Start this service.

Thanks very much, it work. But now how can I change the colour and the opacity of glass effect things? As I remember I used to change it before the service turned down.

Yeah, problems solved! I've run the service Window Manager Session Manager and I did it!!! Thanks you so much!

Did the services.msc work? I don't understand what you mean by "Window Manager Session Manager",

go to Control Panel - Personalisation or Right Click on Desktop - Personalization.

Windows Color.

And change it to your liking.

Colour Transparency and Intensity is related to how transparent it is (no glass).

Show Colour Mixer changes the colours.

You may also need to go to Control Panel - System - Advanced System Settings - Under Performance click Settings, adjust for Best Appearance or adjust it how you like.