No internet - driving me nuts!

Hope someone can help!

A friend has just taken delivery of a Virgin Media all-in-one hub and can't access the internet via the ethernet connection but can via wireless.

I've got the pc here.  Here's the state of play:

Her pc can access the internet via MY cable modem.

My pc can access the internet via HER all-in-one hub.

I cannot get her pc to access the internet via HER all-in-one hub (which mirrors her experience).

So, there's nothing wrong with her pc because she can access the internet just fine via my connection; her all-in-one hub seems fine as I can access the internet via it.....it's just her pc and her hub that don't seem to like each other!

I've tried ipconfig/release etc to no avail.

If I type 192.168.0.1 I can get into the all-in-one hub's setup but there's nothing unusual in there.

Help!  I'm totally confused!