Installing updates on Vista can result in changing the Vista black theme to Classic theme. Your system might also tend to work slower and freeze periodically. Apparently you have way back to restore the theme back to Vista black. however here is a straightforward way to restore your previous theme settings without any hassle at all. You do not need to uninstall the updates at all. Try these solutions:

Solution 1:
Right click on desktop.
Click Personalize
In the Personalize Appearance & Sound window click Theme
Select Window Aero

Note: You might not see any other option in the theme drop down menu. if so is the case try to restart your machine. now follow the same steps enlisted above. You will now find your self with options in Theme dropdown menu.

Solution 2:

Right click on desktop.
Click Personalize
IdentifyAdjust font size DPIunder the Tasks in the up left corner of your window.
Set this to default and restart your machine
Come to Personalization Window (First 2 steps) once again
Click the first option Window Color & Appearance
Here you find a link Open Classic Appearance Properties. Click this link.
Select Window Aero now.

If this is not working, this implies that you have accidental deleted the shsvcs.dll file this file is easily and freely available. Download this.dll file.

You are done. this accidental change of theme from vista to classical view, is annoying and is not properly discussed. therefore I though to explain this simple way of restoration.