Has this happened to you? Suddenly, overnight, you've lost your shares in Windows 7, you can see them but you can't access them, not even from the primary PC where they reside. You check all your permissions and nothing's changed, everything seems perfectly the same as it did when your shares worked the night before but when you try to access them you get an 0x800704cf error - The Network Location Cannot Be Reached. You click on the troubleshooting link, but to no avail .. the troubleshooter cannot suggest a solution.
Check your device manager and see if you've got a plethora of redundant Microsoft 6to4 Adapter clones under Network adapters. You've got to check View and then enable Hidden Devices in the toolbar. Awhile back I found
nearly 300 of these Microsoft 6to4 Adapters! It's a known Windows 7 problem recognized by Microsoft. A further problem is that the solution MS offers doesn't work. Nothing works except to manually uninstall these things because they clone themselves every time you reboot your computer.
Most people aren't aware of the problem until it manifests itself by a loss of shares and then they're stuck with having to uninstall each of those adapters, one-at-a-time, unless they're lucky enough to be running a 32-bit version of Windows. You can use DevCon to mass uninstall them, but unfortunately DevCon (which came as part of the Windows Server 2003 Service Pack 2 Support Tools) doesn't work in 64-bit Windows 7, not even the 64-bit flavor that was written way back when and never updated for this lastest OS.
So do yourself a favor before you suddenly lose you shares: check your device manager and if you see those hidden 6to4 clones, uninstall them now, and keep uninstalling them until MS comes up with a real solution, provided they ever do.