Well its safe to say completely rebooting your computer CAN have it running at its fastest. Since you wont have any spyware installed, nor other programs running in the back ground. But this is not the best choice. Rebooting your computer or reformating is really the last thing you should do. If all fails, you simply do them. So dont just jump on the horse. But if you know a few things about windows. You can indeed delete spyware and useless programs. Without compromising your data.
Click your start buttom, go to run. Type msconfig
then click the page displayed as STARTUP. This is everything thats commanded to start and run in the back ground everytime your system is booted. If you know Windows and your system itself. You'll understand what everything is, what should be there, and shouldent. You dont want programs that you dont use 24/7 to automatically start up.
This is where spyware hangs out. Now you'll notice if you uncheck the spyware, it comes back. Thats because its a howl program installed. So you must delete the program from Add/Remove.
Finished With TF.