Connect two Pc's

Your question leave one wondering why you want to do this. If the two machines are close by then you don't need a modem. You can do this in several ways. If they are not than you would need something like PCAnywhere and connect to one machine.

If you have both machines next to each other and if they have NIC you can connect both NICs with the network cable and assign the same IP address to them. Each machine will then appear as a drive on the other machine. Good luck.

First, you CANNOT connect a modem cable between 2 computers and have them network. The modems require an active phone-line to function.

The PCs MUST be connect to different phone numbers in order to network over their modems.

Then, you need to setup your peer-to-peer or VPN network and have at least one PC set to auto-answer.
Then, have one PC call the other PC.

If this is for a simple home network, there are network adapters that use the existing phone lines. Check out the links at www.homepna.org

Chas

Are you trying to test something? Use a modem eliminator:

http://www.hullspeed.com/me0000a.html
or
http://pcmag.shopping.com/xPO-Black_Box_Async_Modem_Eliminator_ME200