I am running an outdated Windows 7 and am not able to update it due to some reasons. I wanted to know how vulnerable is my Windows to WannaCry from the home wifi network connection. What would you recommend as an alternative solution to keep my Windows protected from it?
WannaCry spreads using windows SMB. One should be able to disable this completely. However i recommend you to update your system. You wont win the hacking race against thousands of people alone...
Block external access to the smb port at the router (139, 445).
Disable smb if not necessary
The usual anti- spam stuff
the usual mail/browser hardening
Fix the 'some reasons'.
That is the simplest option... Unless the 'some reasons' are the use of a pirate version of the operating system, you should be able to get help with the issues that are preventing you from patching on SuperUser.