The How-To Geek has an article on editing the Windows registry to stop the screen from blacking out and locking up when a program need administrator access (i.e., run as an administrator). I found that this is possible while trying a tweaking program named Tweak Me!.
For Windows Vista, you need to edit [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System] and set PromptOnSecureDesktop to 0.
I.e.,
Reference: Make User Account Control (UAC) Stop Blacking Out the Screen in Windows 7 or Vista [How-To Geek]