I have 2 computers which are connected by two network cards and a crossover cable. I have them configured in the same Workgroup (studio) and I have shared both of the pc's harddrives. Still, the computers can not find each other... Could it be something wrong with one of the networking cards, even if the Device Manager tells me that it is working ok? They do not ping each other but the connection icon on the task bar tells me that an connection is established... I have tried 4 differen crossover cables...

Have you assigned each computer an IP address? If there's no DHCP server, the computers will have to have static IP addresses before they will talk.
If you've already done that, I would try buying a hub and using 2 regular cables.

Just set up the protocal as NetBEUI and forget about trying to assign IP if all you are doing is swaping files.

Do you have a firewall that is blocking? Another problem I ran into was having an unnecessary network driver installed on one of the computers that was not being used. It did not play well with the driver that was being used and had to be uninstalled. I agree with binding to Netbeui suggested in the earlier post. Since I cleared these 3 little problems up, my network runs fine.