File sharing problem between two computers

My new Dell Inspiron notebook computer cannot access shared files on my Dell desktop computer. The desktop can access the files in the shared folder on the notebook computer. The notebook computer can access and print using the printer connected to the desktop computer, but cannot access the desktop computer's shared folder. From the notebook I can see the "Desktop" icon under My Network Places -- Entire Network -- Microsoft Windows Network --Home, but when I try to access it I get a Start Menu window that says:

\\Desktop is not accessable. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions.

Access is denied.

Both computers access my home network via a D-Link router. Properties of the Notebook's WIreless connection has the following checked:

Client for Microsoft Networks, File and Printer Sharing for Microsoft Networks, QoS Packet Scheduler, AEGIS Protocol (IEEE 802.1x) v3.2.0.3, and Internet Protocol (TCP/IP). The advanced TCP/IP Settings has Enabvle LMHOSTS lookup checked, and Default: Use NetBIOS setting from the DHCP server...checked.

Properties of the Desktop's WIreless connection has the following checked:

Client for Microsoft Networks, File and Printer Sharing for Microsoft Networks, QoS Packet Scheduler, and Internet Protocol (TCP/IP). The advanced TCP/IP Settings has Enabvle LMHOSTS lookup checked, and Default: Use NetBIOS setting from the DHCP server...checked.

I disabled the Local Area Connection on both computers. For both computers the D-Link Wireless Connection is connected and firewalled using Microsoft Firewall - Under the Exceptions tab -- Programs and Services -- File and Print Sharing is checked, Remote Assistance is checked, and UPnP Framework is checked. (I also have disabled the firewall on both computers, but still have the file sharing problem.)

Each computer has a folder under the My Documents folder - for the Desktop its name is RF-DKTP, for the Notebook its name is RF-NTBK. Both of these folders under Propereties -- Sharing Tab -- "Share this folder on the network is checked."

The name of the Desktop computer is DESKTOP, and the notebook computer's name is NOTEBOOK. The Workgroup for both computers is HOME. I logon to both computers using the same logon name and password. Each computer can ping the other computer. Both computers run Windows XP Home Edition.

The IP address for the desktop computer is 192.168.0.100 and for the notebook computer it is 192.168.0.101. Both computers have the same subnet mask and default gateway.

I would appreciate any ideas about how to correct this.