This tweak will free up processing time from any idle processes and allow it to be used by the foreground application. It is useful particularly if you are running a game or other 3D application. Create a new shortcut to "Rundll32.exe advapi32.dll,ProcessIdleTasks" and place it on your desktop. Double-click on it anytime you need all of your processing power, before opening the application.

Windows Indexing Services
Windows Indexing Services creates a searchable database that makes system searches for words and files progress much faster – however, it takes an enormous amount of hard drive space as well as a significant amount of extra CPU cycles to maintain the system. Most users will want to disable this service to release the resources for use by the system. To turn off indexing, open My Computer and right click on the drive on which you wish to disable the Indexing Service. Enter the drive's properties and under the general tab, untick the box for "Allow the Indexing Service to index this disk for fast file searching."