Whole Computer Scan and Rootkit Scan will not complete

Hi There,

To give the whole story- I was seeing persistant pop ups despite adblock so decided there must be a problem somewhere. I found I had accidentally installed something (or allowed something else to install it) and went about uninstalling anything that looked fishy. After a while the pop ups returned so I decided to upgrade from free and buy AVG in the hopes that it would find and fix the problem - but it returned again. So I installed Malwarebytes (Free) which found over 1000 instances of malware and PUPs. I was really surprised to say the least but glad I'd found it rather than not. Unfortunately the problem came back and, while I'm not currently seeing pop ups, I'm still finding malware with Malwarebytes and AVG found a few things it didn't like too. On top of that, now neither AVG nor Malwarebytes will let me complete a scan to get rid of the problems they have found.

I'm not sure why the scans wont work, how these malware programs keeps appearing, or if the two problems are connected. Any help on how to stop it all for good would be really appreciated.

Thank you