[Dx4win] Need networking clarification

[Barry]

Guys,
Regarding the inability to get one computer to talk, I'm still confused.
Each computer has a name (in my case number1 and number2) as 
identified in the Network ID tab. Also, each computer has a user logged 
on (in my case w2up-1 and w2up-2), which can be seen if you click 
Start, and just above the Shut Down cmd, is a Log Off user cmd. There 
is no prompt for a user id or password when each computer boots up.

Both computers share files back and forth with no problem. The IP 
address of each is assinged dynamically by a router. Several of you are 
telling me there is a name mismatch. Which one? Computer name or 
user name? Please explain the fix step by step. The one or two line 
replies with fixes, assuming I'm a network guru, haven't helped :.(
Tnx again,
Barry--
Barry Kutner, W2UP              Internet: w2up@mindspring.com
Newtown, PA                     Frankford Radio Club