Try these recommendations:
Create Identical UserNames and Passwords for both computers.
On both computers make sure that DHCP is enabled. http://iyogibusiness.spaces.live.com...1ACB!174.entry
Netbios need to be enabled on both computers. http://ttcshelbyville.wordpress.com/...os-over-tcpip/
Try accessing the Shared Folder/Drive by using the IPAddress of the computer that you're trying to access.
Click on Start and type \\IPAddress\SharedFolderName
then press enter. An alternative to the Shared Folder Name could be C or C$
which is the Local C Drive of the computer if you have the entire drive shared.
Please post an update.