Weird Internet access / server 2008r2 issue

[SteveB_NI]

Here is a weird issue that's affecting only some clients in one specific room - no reports of anything happening elsewhere on the network. (so far - touch wood!)

 

The computer (Win 7) is able to log into the network (Server 2008r2) ok & see the users desktop, documents etc. I can write to the server (My Doc > folder created) and see this elsewhere on the network. However I can't browse the internet whatsoever - it just comes up saying

 

I leave the domain and join local workgroup. It gives me full internet access as desired.

 

I re-join the domain and no internet access again at all - even on proxy bypass ports. I also can't ping the 2 domain controllers, yet obviously I must see them ok for the MyDocs / log in to work.

 

Weird issue - anyone shed some light on this? Thanks!