Infected or not?

have been using free versions Antimalwarebytes and Avast for quite some time, i run Antimalwarebytes pretty often. so, yesterday my PC stops responding, basically slowed to a near stop/crawl. nothing is working, several hours for any operations to work. after some reboots it began to display 'windows version 7 not authentic' or something similar. after a search on another PC it appeared i have a trojan horse on seemingly infected PC. shut the thing down. wake up this morning and attempt to use system recovery disk and am prepared to wipe out everything if possible and start over, all important files already backed up. recovery disk only offers choice of a restore so i choose that. PC starts up, and my intention is to update and run the Antimalware. computer is no longer crawling. open Antimalwarebytes and it says has been corrupted/doesn't exist. after a couple attempts i am able to re-install and update it and get a full system scan running. meanwhile i also download and run Microsoft Security Essentials and Microsoft Safety Scanner. not sure if this was a bad idea to have all three going at once or not..? both the essentials and the scanner finished and claimed there were no infections. Antimalwarebytes is still searching but has yielded nothing and is near completion. meanwhile the PC is now running great as if nothing ever happened to it. at no time was there ever a notification that told me something was found and/or removed. can anyone offer me advice on what may or may not have taken place? i am of the mindset that whatever has gotten into my PC has altered things so that possibly nothing outside of expert work could detect a problem. really not sure what to do at this point.

UPDATE: sorry, i did not read the read me first thread before posting. have done so and am following the directions. not sure how to just delete this post so will leave it and update again if i figure out what to do on my own or still need help.

 

suspecting a trojan horse that will be difficult to remove. followed directions from read me first page. completed directions and attached the requested logs. computer seemed to be running ok before i went through this process, my concern is whether or not i have been able to remove a suspected problem or not and if the problem is in fact removable or too tough to take off myself. any help is greatly appreciated, thank you!

 

thank you for your help tim! the computer ran fine until early evening and fell back into a slow crawl to non-reply kind of speed. became non responsive again. after hearing you say you don't think any disabling virus is present i guess i will consider it a hardware problem. thanks again for your help, it's great what you do for people here.