Hosts.txt no longer functions

I use hosts.txt (actually it is just named “hosts” with no extension – it is located in the system32\drivers\etc folder) to block out certain websites. For example, if I wanted to block Google, I would enter in the file:
127.0.0.1 www.google.com

This used to work. However, I recently updated the file and it no longer blocks websites. It is as if the file is not being recognized or something. I had transferred it from my laptop, and at first, Windows ‘blocked’ it as foreign until I ‘approved’ it. Now, there should be nothing impeding its functioning. It is not hidden, it has no extension, it is ready for archiving, so what could the problem be?