Make Aero Peek Display Instantly (or Disable it) in Windows 7

Aero Peek is one of the more useful new features in Windows 7… just move your mouse to the taskbar for half a second, and everything else hides so you can see the desktop or application window. But why does it take half a second?
There’s a simple little registry hack that will change the amount of time between hovering your mouse over the show desktop button in the lower right-hand corner, and the Aero Peek display showing up. The same thing should work for when you hover over an application window on the taskbar.

 And of course, if you wanted to completely disable Aero Peek, we’ve got you covered for that too—just head into the taskbar properties (right-click the taskbar and use Properties), then remove the checkbox from “Use Aero Peek to preview the desktop”.

 If you want to disable Aero Peek on everything, including the taskbar thumbnails, you’ll need to head into System Properties in Control Panel (search for “View advanced system settings”), and then remove the checkbox from Aero Peek there:

Manual Registry Hack to Adjust Aero Peek Delay
If you want to change the amount of time to trigger Aero Peek and tweak it for your own preferences (maybe you don’t want instant, but you want it quicker), you’ll need to use the manual registry hack. The instant variety is downloadable below.
Open up regedit.exe through the start menu search or run box, and then browse down to the following key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

On the right-hand side, you’ll need to find the key for DesktopLivePreviewHoverTime (or create a new DWORD if it does not exist) and double-click to edit it—just make sure to flip the Base radio button over to Decimal before you make edits (unless you think in hex).
The value is in milliseconds, so if you wanted 1 second, you would use 1000, or 500 for half a second, etc. If you want to make it instant, just set to it 0 (which works fine in hex too). The default value is 500, or half a second.
Note that you’ll need to log off, and then log back on, for it to take effect.