By default, on Windows Vista and Windows 7, whenever you are prompted with a UAC dialog the entire screen turns dark and the computer seems to freeze completely. This is done on purpose (Not a bug) to prioritise the importance of this window. During this period, the rest of the screen is un-usable, meaning that you cannot run any other program or access any other location on your PC until you overcome the UAC. This is called Secure Desktop mode and prevents the execution of malicious code (if any). It also prevents some remote desktop applications from accessing the dialog box and that in itself makes it more secure. (Thanks for the tip Tim) However for some users, this temporary darkened screen is annoying, and some people would rather get rid of it… Here’s how to do it.
Note: You must be logged in as an administrator to accomplish this.
You can accomplish this in the following way:
1) Open Local Security Policy Editor (Right click on Computer, and click on Manage) and expand Local Policies \ Security options branch in the left pane.
2) Navigate to the option User Account Control: Switch to the secure desktop when prompting for elevation and double click it as shown above
3) Select the dot Disabled to turn off Secure Desktop or prevent screen from freezing when prompted by UAC
4) Click OK button
5) Close Local Security Policy Editor