unwanted dialog box

[joel]

I keep getting this, and it happens for no reason most of
the time. A box appears while I'm navigating the web
saying:

The web page you are viewing is trying to close the window.
Do you want to close the window?
(Yes/No)

Any ideas what it means, and how I can stop it happening?

 

[H Leboeuf]

Try this: Tools > Internet Options > Advanced > Browsing
Uncheck the Enable 3rd party browser extensions

If this clears your problem then find out who the culprit(s) is/are with
these tools.

Let AD-Aware Scan your system for advertising Spyware
http://www.lavasoftusa.com

and:

SpyBot-S&D
http://security.kolla.de/

p.s Reset the 3rd party browser setting.

More: This may be caused by a third-party program (adware, spyware,
parasite).
Get AdAware and SpyBot and run them both. Keep them up to date.
Dealing with Unwanted Spyware, Parasites, Toolbars and Search Engines
http://mvps.org/winhelp2002/unwanted.htm