Can't connect

I have a laptop with a "Linksys EtherFast Integrated 10/100 CardBus PC Card(PCM200)" PCMCIA Network card. Its a Dell CPx J and running windows XP pro (sp1). We have Adelphia power link (cable internet) and the I am not aloud to network with a router or anthing because they don't want me to drill holes. Second they don't want a Wireless router for... I don't know why they just don't. Regardless I have been unplugging their computer from the cable modem box and have been plugging mine into it. I use to get a connection after 30 seconds or so. Well recently everytime I try It won't connect. I checked to make sure I was using DHCP and Had no static Data. I updated the Card's drivers and I tried the good old reboot. nothing has worked. It doesn't appear to pull an IP address, gateway, subnet, or DNS server. Is there anything that anyone can think of that could help me out? Thank you.

Also any suggestions about my networking problem would also be helpful.

Dell Latitude CPx j
650mhz PIII
256 MB RAM
Windows XP pro SP1
12 GB HDD
Linksys EtherFast Integrated 10/100 CardBus PC Card(PCM200)
Cat5e Cable with RJ45 connectors

 

Who is "they". Your cable ISP locates your computer by the MAC address of your network card. The ISP may only allow a limited amount of MAC changes. Ask "they" to reconsider their stance on routers, or find a program to change, or spoof, your MAC address to the same one as the other computer so the ISP thinks that the same computer is connected.