I have tried from my office it show available download site. Then I used same installer (setup-x86_64.exe) at home it not show anything. Both my pc (office and home) i set up go
Just go to website https://cygwin.com/mirrors.html
Chose the mirror web address nearest to you by clicking right and select the option "SAVE LINK ADDRESS" from the menu.
Paste it into the "USER URL" then click "ADD" and press "NEXT". Hope it will work. Good Luck.......!