my pop-up windows wont work

hello everyone
I have a Systemax Encore machine with Windows XP
recently when I have been using some sites where before a chat dialogue box used to open, for some reason I cant get them to open anymore. Has anyone got any ideas please??

 

have you installed a pop up blocker recently? Or the google toolbar?

 

pop-ups;

no task google bar
six computers run off a dell host machine
are all the settings controlled from that?
(I told you I was thick, ha-ha)

I had a blocker on the host computer, but I have disabled it.