Help needed with new modem

[cmbb421]

In July a big storm came through and took out my aunt's modem. I purchased a Best Data 56SF92 modem and attempted to install it. I uninstalled the software on the original modem, took it out of the case, installed the new software, and installed the modem. I tried to connect to the internet and there was no dial tone.

So I checked the phone line. It didn't connect, but could still pass a dial tone from both the phone jack and the phone connection on the modem. I disabled detect a dial tone in the modem properties, but resulted in no connection.

I took it to a friend who checked it out, and said that everything was working properly. So I took it home and still couldn't get a dial tone.

After I got the computer back at my house, I tried another PCI slot. Actually, I tried 3 others slots and got the same result with each of them.

By the way, there is nothing wrong with the phone line. I took my computer and plugged it up to the same phone line through the same connection, and it connected fine.

I'm using NetZero ISP and downloaded another copy to her computer, and after installing and registering, NetZero still did not detect a dial tone. By now I'm thinking that the modem's bad, so I took the modem out of my computer (that I could connect to the internet with) and replaced the one in her computer with it and vice-versa with my computer. I could still connect to the internet through my computer, but not with my aunt's computer. So both of the modems work, just not on her computer.

What should I do? Here's the computer stats:
Mine: Windows xp Home Edition
Compaq Presario PC
Her's: WIndows ME
Gateway 2000 PC
Modem: Best Data 56SF92

[cmbb421]

I've also installed a new CD Burner and DVD-ROM. This is the link to the other thread. http://www.techimo.com/forum/t119501.html .

Could these two issues be related? Please let me know