Connection not detected

My desktop computer running Vista is unable to connect to my broadband connection through my modem (DSL 502T) and a 12m ethernet cable. It does not detect any modem or connection whatsoever and a red cross appears over the internet tray icon.

I don't think the problem lies with the cable as I'm able to connect to the web if I use the cable with an alternative modem (RTA 5020a). And I don't think it's the modem itself since it connects fine if I use the modem with a phone line extension and an alternative, shorter ethernet cable, instead of the longer ethernet cable alone (my computer is some distance from the phone jack). But obviously I want to use the ethernet cable over the phone line extension.

To further complicate things, my laptop (also w/ Vista) has no problem connecting to the internet using the original modem (DSL 502T) and long ethernet cable together.

So I'm guessing the problem lies with the system/software settings on my desktop? Device Manager shows no conflicts or alert symbols on my Network or Modem adapters.

Help!

Hello & welcome,

First & I know this is a daft question but do you have SKY TV & are you trying to connect to the same socket?

The reason for asking is: -

I had a similar issue with my SKY HD TV plus box. The ONLY answer was to use a phone extension!

Other than that, I stumped at the moment.

Hi Lottie!

No, I don't have SkyTV, and I'm not really sure what my sockets are doing or what they even are.

Cheers