https://www.sevenforums.com and
http://www.tomshardware.com are good forums.
There are also probably better ones out there.
I was having the same problem but it turned out to be a MSSE bug running the CPU and fan at 100%.
Reinstalled and then eventually switched to Malwarebytes and the roses are shiny again.
(Well not perfectly shiny. A process called com.surrogate still tends to corrupt my thumbnails and slow down clicks. Plus an occasional BSOD to let me know who is boss. And KB4343900 is a frigid tease sent to destroy humanity.)
Do a start->run->
msconfig and uncheck/kill all startup programs like Outlook Skype or anything that doesn't need to be running in the background all the time even when not in use.
Services.MSC is another important line command used to fix things.
(That is where my pay grade ends)
There are also bitcoin viruses going around which use your computer energy to 'mine'.
Spybot or others will probably get those.
Also clean up temp file with CCleaner and defrag overnight with something quality.