It isn't a wireless networking problem, as you can do network things over the connection.
It is a Windows Sharing and NTFS Security problem.
1) Set up shares on the PCs as required.
2) Ensure that you provide at least Read access at the share level.
3) Configure NTFS security permissions as required.
Now MAP a drive from 1 PC to the other - Tools\Map network drive. Choose a drive letter, enter the target share in the form \\PCname\sharename and select connect using a different name. Supply a valid username on the target system in the form PCname\username, and enter the password.
You should now make a connection.
SD