Your problem most likely is Advanced System Care (ASC). ASC is a security software that users here have reported being a problem and conflicting with other software as well as Avast, and they have needed to uninstall it for their machines to work properly. Not only is it a hog on your system, but it also leaves remnants behind. It is related to IOBit, which is doing some shady business lately.
To uninstall ACS, follow the vendor's instructions, then reboot. I also recommend going into Safe Mode > All Files and Folders > Search > Advanced Options (make sure all boxes on the bottom are checked off except case sensitive) > type in the top box Advanced System Care > click "OK." Repeat the same steps but this time type in ASC. Anything that comes up in the right-hand pane you can delete, however if in doubt of a file, right-click it and check "properties" to see if it belongs to ASC...if it does you can delete it. Empty your recycle bin from Safe Mode.
Also, check to see what you have running on Start Up (when you machine boots up). Any unnecessary programs, you can "disable" (NOT delete) to speed things up.
Let us know if this helps you. Thank you.