None of the workstations (including the server) is able to access any web pages within one of our offices. However, I know that there is an active ADSL connection because I am able to remotely access the server using Remote Desktop Connection. I am also able to copy and paste documents to this server from my home.
I can access the router control panel via the web from the office server but when I try to access an outside web page I am unable to, even when using an IP address.
The only evidence of a problem is if I try to ping something, I get an error "NTVDM encountered a hard error"
I have run a virus scan with 2 different products (ESET & Malwarebytes) but neither have found anything problematic.
This problem started happening on Friday. No changes were made to the ADSL router beforehand and we have had no previous problems like this since the router was installed 2 years ago.