Let's work Permissions for awhile.
1. Are both PCs in the same Workgroup or Domain on your LAN? Right-click My Computer, click Properties, click Computer Name, click the Change button (but don't change anything) and verify each computer is in the same place.
2. Can the PCs ping each other? Go to a DOS window, enter IPCONFIG /ALL, get each PCs IP address, and issue a >Ping IP_Address to each other. If the computers are in the same Workgroup or Domain the IP adresses should be VERY similar.
3. Check that File and Printer Sharing is checked on both PCs (mainly the one you want to copy FROM). Go to Network Connections, right-click the Local Area Connection that is Enabled for your LAN ethernet connection, click Properties, be sure File and Printer Sharing for Microsoft Networks is Checked.
4. On the PC that you want to copy FROM, go to the folder you want to copy FROM, right-click, click Sharing, share folder as some name, click Permissions, and set to EVERYBODY Full Control. This is TEMPORARY (actually, Read Only should be sufficient). Do not leave it at Full Control indefinitely unless you specifically need that.
5. On the PC that you want to copy TO, right-click My Network Places, click Map Network Drive, for Folder enter \\FROM_PC_name\Share_Name or enter \\IP_Address\Share_Name, such as \\126.96.36.199\Share_Name. Click Finish and if it asks for authentication enter FROM_PC_name\admin_name and admin password or IP_Address\admin_name and admin password, such as 188.8.131.52\administrator and password. NO double back slashes for authentication. Click Finish if asked.
6. The FROM folder should open in Explorer on the TO PC. Copy and paste.
Be positive! (A blood type?) We can do this.