The Sysinternal Suite also comes with a tool that will show you if your computer has a rootkit or not.
After only a quick glance over the screenshots I didn't see too much problematic things. However, there are 82 processes running on your system. That might be a bit on the high side. This could also mean that you are running out DHEAP
memory. Although Windows 7 and up handle this much better than earlier Windows versions, you can still run out of it and in that case it really doesn't matter how much free RAM is still available in your PC. Running out of DHEAP will make your system become (extremely) slow and applications/services won't be able to start anymore. Behavior that is usually associated with PC virus/malware.
There is also the possibility that you ran out of threads. Processors come in various shapes and sizes. Each with their own, finite amount of threads they can handle. Each process uses a certain amount of threads, depending on its function or what it is currently doing. Running out of threads will make your applications/services slow and you won't be able to start more of them no matter how much free RAM your system still has left. Behavior that is usually associated with PC virus/malware.
In both cases, the best solution is to identify which of the 82 processes running on your computer is from a 3rd party (easily seen in Process Explorer). Then identify which of the 3rd party processes are essential to you and and terminate the rest. Then your computer should be much more responsive and allow you to disable autostarting crap (SysInternals Suite tool: AutoRuns).
Get familiar with the tools in the SysInternals Suite, there are a lot of them and are very, very helpful. The archive is just a 13MByte download and is provided at no cost, so there isn't much to lose.
Keep your PC lean and mean by starting applications/services only when you need them and terminate these when you are finished with them. Lots of software claims it to be essential that it is started the moment Windows starts. Besides security software (anti-virus/anti-malware/firewall) there isn't much software that really needs to autostart with Windows or kept resident after you are finished with it.
This will free up a lot of the limited resources at your computer's disposal and make your computer behave better in general. If you would be a doctor, your computer the patient and it's resources the amount of health it has...would you really think that leeches are still a good treatment? In my (not even close to humble) opinion, it isn't.