Dial-up connection dialog box

I recently changed from a landline broadband modem (USB connection to PC) to a landline broadband modem with wireless LAN capability. My desktop PC connects to this using a Belkin wireless network card. Prior to this I had being using the landline broadband modem for at least 2 years, i.e. it's been at least 2 years since I used a dial-up connection on this PC.

Since I went wireless, I get a dial-up connection dialog box most (not all) times I load new web pages (WinXP SP2 & Firefox 1.5.0.8). It's trying to access an ESAT dial-up service which, as above, I haven't used for a couple of years.

It could be related to the PC no longer having a physical connection to a phone/modem. I've looking through Firefox Tools > Options and can't see anything obvious there.

I thought it might be some malware trying to dial out for nefarious purposes but neither Skybot Search & Destroy nor Windows Defender could recognise anything wrong.

Any suggestions how I can stop this happening ?

In IE go to Tools -> Internet Options -> Connections and if the dial-up connection is listed in the Dial-up and VPN Settings list then select it and choose Dial whenever a network connection is not available or maybe even Never dial a connection and see if that helps. Even if you are using FireFox I think that you need to do this to configure Windows not to dial-up unless necessary if at all.

Thanks for pointing me in the right direction.
I found what I needed within Control Panel > Internet Options

Glad you got it sorted.