These are the Methods I use for PC cleanup. These methods will clean up temporary files, put files in order for quicker access, and remove malware and spyware.
(Video will be available 1-16-2017 530pm Pacific Time zone.)
I start by removing all the temporary files from my PC. When you use programs, they store files they use temporarily but do not remove them. They use up space and often slow down the PC. There are also cookies used to track your web use and this method also clears those out. I use CCleaner (Not affiliated).
I then run a program that puts the hard drive files in order. Think of a spinning record and how your computer may wants parts from each song. When you De-fragment your hard drive, the files are put into order to make it much quicker to access files. DO NOT DEFRAGMENT SSD (Solid State) HARDDRIVES! This is not needed, and is bad for them. This is good for all spinning disk hard drives. I use Defraggler (Not affiliated).
Next I run a scan for Malware using Malwarebytes (Not affiliated).
Then I run a scan for Spyware using Spybot-S&D (Not affiliated).
Running these 2 scans are not enough to protect a machine, but its a great start.
Next I would setup an Antivirus and run system scans weekly (Or daily for more sensitive data). Please do your research for the best antivirus as they do vary between companies. A few free antivirus are Clamwin, AVG, And Panda.