windows defender

Hello, I wonder is Windows Defender enough for Windows 8.1 security? I see that it can be easily bypassed from registry or powershell.

So lately I've noticed some things about my computer that I need help on. So just to let you all know; my birthday was last month, and I have a brand new desk that places the hard drive inside the drawer instead of on top the desk. Because of its size, I can't close the door. Also, before all of...