It's really easy to mess things up, when you do things like registry tweaks, or shutting down services, changing windows settings, etc. *
Personally, I've taken all the speed up tweaks and things like that and (very carefully) written them into batch files and registry scripts,
that I can run on any PC with NO worry about screwing it up.
I just did another computer today and just about doubled it's speed, along with taking out thousands of junk files, removing a serious Trojan, one Virus and over 30 pieces of Spyware. (My Web Search, was the worse!)
Just a thought....
* System Restore is always your first line of defense, against a Windows Update or some new piece of software mucking things up. Why some folks shut off that valuable app, is way beyond my understanding. I rely on my own System Restore so much, that I put a little .reg script in my Startup folder to force a new restore point every time I reboot my PC. I need to do a System Restore about once a week to fix some little problem or another.
I share that script with all my customers, so I have something to work with if they call me out to fix their PC.