reible wroteAdware is designed to present ad's and as such they don't want to harm your computer. It is unlikely that it came from visiting a site but more likely to be added when you install something. The program may even tell you that it is adding something that sounds harmless and it is harmless but more of a pain in the you know where.
I noticed a few names of possible sources:
PDFPoof, BatBitRst, MessengerNow, SearchAd, MyPrintableCoupons, Reading Cursors, ProMediaConverter, PDFOnline-express, See Scenic Elf, Clickware, Easy Speedtest, or WebDiscover.
I'm sure there are more but I would start by looking for installed programs with these names or some other names that might not be something you remember installing.
It will also be something on both computers. And uninstalling might not be enough. Since it is not a virus per-say and often something you actually installed your protection software may not find it.
Ed
I just finished running all of my protection software with NO revealing results. As you surmised, all of the offending popups are some sort of adware presentation.
