Errors when trying to update Debian 7 APT Cache

When I’m trying to make update (with apt-get update) in Debian 7 I always have errors like this:

W: Failed to fetch http://security.debian.org/dists/wheezy/updates/non-free/binary-amd64/Packages 404 Not Found

I tried changing servers in sources.list but nothing works

Try apt-get clean. That should clean the cache and then you should be able to do apt-get update.