Check out this program ... WinPatrol Plus for the PC. This is a slick little utility that will allow you to govern almost all aspects of what gets turned on and off at system start. Resources, Hidden apps, the works. You can get a free version of it to run and after using it for some time I finally paid the guy for the Plus version because I think he deserved it.
Here is the link ....
http://www.winpatrol.com/
Give it a look - you may find some things under the hood that may be effecting performance.