After installing VMware in Windows Vista or 7, there are two public networks that can't be identified, but upon further inspection are virtual networks created by VMware. The problem is when you're on a Home network, these "Unidentified Networks" are still there and mess up file sharing settings, among other things.
Per this site:
Click Start, click Run, type regedit, and then click OK.
Click the following subkey:
Browse through the 00xx subkeys until you find the REG_SZ VMNet subkey with a value of either “\DosDevices\VMnet8” or “\DosDevices\VMnet1” (default values)
On the Edit menu, point to New, and then click DWORD Value.
Type *NdisDeviceType, and then press Enter.
On the Edit menu, click Modify.
Type 1, and then click OK.
Exit Registry Editor.
Disable & re-enable the VMWare NICs
Log-out of your Windows account and log back in.
Or, optionally, use this powershell script to do the same thing automatically. This is most useful in Windows 7 which has PowerShell built in.