One setup that usually work is if you install Service Pack 3 on all NT 4.0 machines. If you are going to use any Win95 clients then you'll have to install DCOM for Win95 on those machines. You'll also need Microsoft Internet Explorer 3.02 on the client machines. On the machine were the application server is going to run (an NT 4.0 machine) you'll do each of the following: Enable the Guest account. This is disabled by default. Make sure the application server is on a local drive on the machine. Run the application server once to register it. In DCOM Config (dcomcnfg.exe) for the specific server object: On the Identity tab, select "The interactive user". On the Security tab, select Custom Access Permissions, and make sure EveryOne is added and allowed access. On the Security tab, select Custom Launch Permissions, and make sure EveryOne is added and allowed to launch.