The question, "Is Windows 7 (or any other version) safe..." - is always going to draw many different opinions. Basically, it comes down to what you do online, how often, how much knowledge you have re: internet safety, and how much uncertainty you can live with (or, another way to put it, how paranoid you are). We all have our sweet spot in that regard. Mine, as I have said many times on this forum, is to use W7 for the one thing I really need it for, music creation. I keep it offline by default, but go online if I need to (but not to just surf the net). I update MSE when I do so, and run a quick scan afterward. Then I disable the network adapter. For my everyday browsing, I use Linux mint on another computer.
Other folks of course have different sweet spots. To each their own. If what you are doing is working - you are not getting malware - great. Hopefully things will stay that way. If you do get malware, you will need to do things differently.