Windows Flip 3D, which gives you a pop-up preview of all your open windows, is one of Windows Vista's coolest new features -- but if your hardware isn't up to snuff, its operation can be jagged and sluggish.
With a Registry tweak, you can speed it up and smooth its animations by limiting the number of windows it will display.
>> Launch the Registry Editor by typing regedit at the Start Search box or a command prompt.
>> Navigate to HKEY_CURRENT_USER\ Software\Microsoft\Windows\DWM
>> Create a new DWORD value and name it Max3Dwindows.
>> Set the value to the maximum number of windows you want displayed. If you have severe performance problems, set it at 4; you can always re-edit and up the number later.
>> Exit the Registry Editor.
For the change to take effect, you'll need to either restart your PC or restart Vista's Desktop Windows Manager (DWM). To do the latter, launch an elevated command prompt (which means you're operating the command prompt with administrator rights) by typing cmd in the search box and pressing Ctrl-Shift-Enter. Type net stop uxsms and press Enter. Then type net startuxsms and press Enter. Windows Flip 3D will now be sped up.
With the new settings in effect, Windows Flip 3D will display only the number of windows you've told it to. If you have six windows open and your set maximum is four, only four will be displayed at a time. As you scroll through your windows, each new one will replace an old one.