Well, that explains a lot.
The advanced system care 10 is made by IObit I believe, and that carries quite a payload of spyware viruses in it and I remove it from every system I see it on. It's definitely not on my approved utilities list. Just because you can get something for free doesn't mean it's going to work well or be virus free.
As neem mentioned, that's one of the biggest problem with windows computers in general, and that's people downloading utilities they find randomly on the Internet that claim to be a panacea to fix all the problems with your computer--and most of them don't or can't do what they claimed. In this case, we tried buying a license for the paid version of the ASC (advanced system care) and it still comes with Spyware viruses! Ugghh! Get rid of that, and install a quality AV such as Norton, Avast, TrendMicro, or even McAfee. Run the CCleaner as recommended. That should speed up your system.
If it doesn't you should consider hardware testing as any system built with W8x probably is experiencing failed RAM or Hard Drive by now. Use my troubleshooting guide here to do this:
Windows 10 - Unclickable Task Bar
Replace any failed hardware components, and reinstall your W8.1 from factory Recovery media and that should take care of most problems. If it doesn't, you may want to pay a licensed computer pro to take a look at your system and get an analysis done by them.
<<<BIGBEARJEDI>>>