That really looks like a probably cause. Holy cow
All the processes eat alot of memory at startup which makes the entire system lag. By Disabling the less essential process's at startup, it might also save you CPU life in future instead of burning your CPU out, and hammering your poor pc.
The more programs you install on your pc, the slower it starts up. Try also un-installing old, and unnecessary applications and software that you dont really need.
Not only will it free up hard drive space, but it will also end a few un-needed CPU eating apps! Only enable essential applications for startup, and see the difference after a while!
Also, to make matters a little easier for your pc, do a defrag at least once a month so to speed it up and defrag the drives. Even if it says it doesnt need to be defragged, do it on a perpetual basis.
A good app to get for helping optimize system performance is Ashampoo WinOptimizer.
Also make sure you update your antivirus often. There might be hidden applications running in the background that task manager might not see..