Are you able to connect to iTunes' Store?
My old iTunes v12.6.3.6 (old version to keep its app feature), in an updated 64-bit W7 HPE SP1, can't right now. It was fine yesterday. My iPhone 4S' iTunes store currently works fine too. https://www.apple.com/support/systemstatus/ shows green OKs. 😟
iPhone 4S, iOS 9.3.5, 64bit W7 HPE SP1 & Verizon Wireless