The only other thing I can suggest is to google keywords - the name of what's appearing, the website and the issue with the ad appearing. You may find some help articles or threads on other forums that have advice on how to fix or remove. 

My sympathies on the scan time 😮 😛 If you don't have it already, something like CCleaner could help (also a free download), it's quite good at some of the upkeep tasks, getting rid of irrelevant and useless files on your computer, and that can sometimes help make things run faster / smoother if it hasn't been done for a while.