I'm assuming you have Win 2K or XP -
If you have Windows NT, 2000 or XP you should always use CMD.EXE rather than COMMAND.COM - unless you have to run a legacy 16-bit DOS program that won't execute correctly in CMD.EXE.
For one thing it has support for LONG FILE NAMES!
It also has support for far longer command strings and environment variables than COMMAND.COM.
Anyhow, back to the question - using a CMD prompt, type IPCONFIG / all to see what the IP settings actually are.
Report back, including O/S info.