Is there a fix for the continual disconnecting while two users are logged in?

Hi, First, I would like to confirm the following questions: 1. Is the computer a home computer or a work computer? If it is a work computer, is it in a domain or a workgroup? 2. How does the computer connect to Internet, via DSL or router? 3. When the issue began to occur? Does the issue occur if only one user is logged in? Please refer to the following suggestions to troubleshoot the issue. 1. Temporarily turn off firewall on the computer or router (if it has) to check the result. If the issue persists, please bypass the router or switch for a test. 2. Update the network adapter driver for Windows 7 (or Windows Vista). 3. Perform a Clean Boot. Then Log off one user and switch to another one. Thanks, Novak