W10 Guest VM doesn't see Host W7 Homegroup

Computer Type: PC/Desktop
System Manufacturer/Model Number: home built
OS: Multi-Boot W7_Pro_x64 W8.1_Pro_x64 W10_Pro_x64
CPU: AMD Athlon II x4 620
Motherboard: Gigabyte GA-MA785G-UD3H
Memory: 6GB GSkill DDR2 800
Graphics Card: AMD 4670 GPU + AMD 4200 IGP
Sound Card: on board Realtek ALC889A
Monitor(s) Displays: RCA 40" LCD TV, Insignia 32" LCD TV, HP 15" LCD monitor
Screen Resolution: 1680 x 1050
Keyboard: Gyration wireless, Logitech wireless, Dell USB wired
Mouse: Gyration wireless, Logitech wireless, V7 USB wired
PSU: Corsair 500 W
Case: Rosewill mid tower
Cooling: CM 90mm rifle
Hard Drives: OCZ Vertex 3 120GB, Samsung F3 1TB (3), Several others - WD, Seagate, Hitachi, ...
Internet Speed: Uverse - 12Mbps D / 1.5Mbps U
Browser: Pale Moon, IE, Edge
Antivirus: WD, +MBAM +EMET +WinPatrol +Zemana AL
Other Info: 2 multi-boot PC's. Mainly HTPC/Gen purpose (no gaming). Trendnet USB KVM. LG DVD burner/Blue Ray Player. Tray system for removable SATA backup drives. Not currently OCd, under-volted. I use Hybrid sleep, rarely re-boot or shutdown. Hauppauge HD-PVR, Avermedia PCIe TV Tuner, Hauppauge PCI TV Tuner.