Its a professional blue band under the toolbar and at the left that's what it says, with a turning circle of dots going round. Never seen it before, and even a reboot won't stop it.
Run CCleaner several times.
Disc activity reaching into logical drives.
What I've done today is to look for a driver for Bro's scanner. It won't run on new W7. Got lead down a path to what was one of those driver companies. used the Get me out of here! button on the Windows warning.
To my horror, I found that it was also running on E8. So, it was a waste of time uninstalling FireFox. Why didn't I check first?
Rand AVG for about 90 mins, nothing but my camera, which is the only thing that is running in XP mode.
Anyway, went back to an earlier point, and hey presto, Gone.
But, like that, I'll never know what it was.