I'd stay away from "Tune-up" programs, often they do more harm than good.
I would run a virus/malware scan first off, then I would evaluate what processes are starting up with your machine, and disable those that are unneeded.
You could do it manually or with free software.
Manually: Disable needless processes via Services.msc (For power users, knowledge of programs that are required to run on the OS required)
Software: I highly recommend Soluto
. This particular software will scan your system and give you detailed information on what each process is for. It will then give you the option to disable them from starting up, or leave it be.
In short, this is likely going to boil down to malware or a lot of crapware/bloatware being started with your computer.