Hello,
I am a senior technician in the field and I hear of many quick fixes and tools for getting just a little more out of your system.
Most of the tools I have found work well like CCleaner and other tools that remove unused files, but I would not suggest altering Windows system files unless there is an actual need to and the fix listed on MS website calls for it. Here is a posting I have
found for you on this item from a outside party, hope it shines a little light on it for you.
http://askbobrankin.com/windows_prefetch.html