Hi , befora a year i changed my router , and shares disapear. After that i installed again clean Win 7 x64 and network share appear again 
5 or 6 months later i changed my NIC with new one , and again network shares disapear … i tried everything , registry and etc = no result. Once again new install ot Win 7 x 64 and shares appear. My router is TP-Link 1043ND , before 2 days i upgraded him firmware … and again shares disapear ??? I’m tired of preinstalling Win ??? The problem is not software , over 12 years i assembling computers and laptops and running soft on them ?? Please help ?
I am guessing that it’s because your Win7 box is creating a new NETWORK PROFILE.
Mine did that twice when I was replacing my FiOS router.
If it creates a new network profile, all your sharing settings get returned back to default.
Ok , i understand you … but any decision ???
