Ipconfig, Ping, doesn't understand the internal, external command or batch file?

Greetings,

I just moved into a temporary apartment and turned in the leased modem to my old broadband cable provider. When I ordered service to my new provider they asked for my MAC address and I did the old run, cmd, ipconfig /all to get my physiacal address. For some starnge reason any o the network commands are not working? If I type in Ping, ipconfig or anything it gives me the subject line error messages like it is not understanding networking.

I do undertsand that I can't find an IP since I don't have a physical modem or anything connected to the Network cable but I thought I was still going to be able to get the MAC address? I just got into work and unplugged me network cable from the wall (running windows 2000) and it just says media disconnected but still gives me my MAC).

I run Windows XP proffessional and thought I used to be pretrty good n understanding these things but I am actually at a loss. If I try to go into network connections to remove the LAN connection to start over itwon't let me delete it? It seems something is still tied to the comcast connection and won't let me release it? 

What gives?

Dell Dimension 8100
P4 2.4MHz (Powerleap)
Windows XP Pro SP1
XP2 Bios
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1702FP Monitor
Western Digital 40G Master
Western Digital 120 Slave
Soundblaster LIVE Platinum
Logitech cordless freedom Keyboard & mouse
Pioneer DVD-R 105
Samsung DVD-ROM
Pyro IEEE Webcam
Surfboard SB2100 Cable modem (Yes, cable modem in 1997)
Logic IEEE 1394 OHCI
Canon ZR40 DV video camera
Canon powershot S300 digital camera