probly right about the AV entries showing in the HJT log.. I skimmed through and saw multiple AV app's listed, mainly (windows defender) and (eset/nod32) so that I why I suggested to have just one AV installed/running.. Thats OK if it was just an AV online scanner that doesn't have realtime protection/background processes that continue to run, after the scan's are done, but the HJT log shows that there are still multiple AV services running, If you are using nod32, and keep it updated, I don't think you need windows defender.

Have you tried turning off the steam service? I noticed major slowdowns on a couple other computers that had steam installed/running in the background, after closing the application/stopping the steam service, the computer/s were back to normal.

[edit], another option that I've read about regarding nod32+defender is that you uninstall nod32, then temporarily disable/turn off windows defender, (you want to be unplugged from the internet durring this time) then re-install nod32, update it, then re-activate defender, reboot=both programs working on one machine without conflicts.