When I log in to this site I keep getting a pop-up box titled System Settings Change "You must restart your computer before the new settings will take effect. Do you want to restart your computer now?"
Can anyone tell me what this is likely to be & how I can block it?
Quite apart from the time it takes on this PC I am concerned about what might happen if I were to click "Yes".

is it spam??? did you run your anti spyware programs, etc?

I thought spam was unsolicited email so I dont quite understand how that would account for the problem.
Thanks for the suggestion. I run Ad-aware (from Lavasoft) CCleaner & frequently delete files / objects from Internet Explorer via Tools /Internet Options & finish by clicking on Start, choosing Run & typing %temp% . I then delete all files I find there.
It seems to happen only while on this site.

I was seeing that a few times about a week ago, I thought it might have been my machine but it occurred on all my systems here and my system at work. I also noticed that it only happened when a specific ad for some kind of broadband phone service(not the Vonage one) would come up in the banner at the top of the page. A few days after I first saw it, it mysteriously stopped.

I also havent seen that particular ad lately either though...

I thought it might be some sort of advertising - thanks for that observation. I just could not understand how ads. could pop up when I have a pop-up blocker on a Yahoo! toolbar. Actually there is a bit of info. on that blocker "how come I am still geting pop-ups?" I will investigate.
Thanks for contributions> I will turn my attentions to some of the other problems on this rather unstable set-up !