Just some points.
- 'not found': what not found? Internet, page, network, driver?
- did things work before you changed 'netcard'?
- has it ever worked? what changed since?
- assuming pppoE (ppp on Ethernet), there are still two variants, either the modem/router connects or you have to connect with software provided with the ISP, and of course, everything has to be configured correctly (most ISP provide some programs to help a little bit)
- try uninstalling everything, and reinstalling things according to the instructions you got when signing on to the ISP
- does ping work? does mail work?
- all Internet and TCP/IP-options correct?
- using a router?
- what browser?
- does another computer (with everything you got from your ISP freshly and correctly installed) work?
- all indicator lights on the cable modem showing up correct?
- paid your monthly fee?
- what does winipcfg say (and what should it say according to the helpdesk?)
- any history of spyware? if so, tried the lspfix-patch?
- does the ISP offer the possiblity for a dial-up connection; if so, does that work?

I'm afraid you'll have to do with their helpdesk or local knowledgeable support (friends, relations, techs). Unless, of course, you can provide just the right information for somebody here to get a bright idea.

Kees