I'd download and run the free version of CCleaner (you can stop processes starting at boot from there as well as clean up temporary files etc). I'd then install the free version of Malwarebytes and use that to check for nasties that avast may have missed. I'm wary of 'pc tune up utilities'. The only one I trust is CCleaner.
Hands-on: Acer Predator Triton 700 review