Telnet or HT from W2K Pro to Cisco 2513

I installed a fressh install of W2K Pro to a system that previously had been able to Telnet and Hyperterm into our Routers. Every other system can still access the router, which is on the other side of our Proxy server except for the system with the new install of W2K. Any ideas why I’m unable to access the router with the W2K system?