I have a Mac Pro running OS X 10.8.4. It’s networked to a Win 7 machine. I can map the Mac to my Windows box and access files on the Mac from Windows. The machines connect through a switch and employ 10-dot IPs. No router. They are in the same workgroup with the same user account name and password on each. Firewalls are disabled. I am an Admin on both units. So, why can’t I open, copy, delete, etc., any file that I try to access on the Win 7 machine from the Mac? For example, if I try to view a plain text file, Mac says that it cannot be opened. If I try to copy the file to the Mac desktop, Mac says that I don’t have permission (I do in Windows). I can, however, copy a file from Mac to Windows, although I cannot open it from the Mac thereafter. Everything is fine on my Windows-to-Windows network. I've ruled out antivirus. The shared Windows volume is M:\. The user on Win7 is ccu and he has full control over the M:\share. To map the PC from the Mac, I use Go\Connect to Server and enter smb://10.10.10.11/M. I log in as ccu. From the Mac, I can open the PC’s folders and view their contents, but that’s as far as I can go. I'm pretty sure that the Mac is set up correctly. Still the problem only presents on the Mac. There is one Win 7 machine on the network that I can access normally from the Mac, but that machine seems set up like the ones that have the issue. Thanks for any help!