A Window that has an icon associated to it will allow the Window Properties to have a path that uses UNC and does not include a drive letter, like the following.
The Build Tool will give the following error.
Stub_icon: Unexpected format to RCID command.
NMAKE : fatal error U1077: 'C:\Apps\gen\VS100\stub_icon.exe' : return code '0x1'
Resource compile for Stub failed with errors.
File Not Found
Change the path to the icon in the Windows Properties to have a drive letter, like the following.