You have installed a network card in your NT4
system, loaded the
network-drivers , but on starting up
NT4, the following message is displayed:

Also, it will be impossible to share drivers and printers,
because the "Share
Selection" will not be available
in the Context menu (Right-mouse click)
In such cases, ALWAYS have a look to the "Event Viewer" (part of the Administrative Tools):

Double-Click on the "blue" line to get a detailed
error-description:

If you get this message, verify whether you have the "NT4
Service Pack 3" installed by calling up "NT
Diagnostics" (Administrative Tools):

You have the "NT4
Service Pack 3" install, you installed
the Network, but you DID NOT re-install the Service Pack !
Remember: when you installed the
Service pack 3, what it told you as LAST message:

Solution: Re-install the Service
Pack 3