If you are on a Windows machine running 8.1 (and maybe previous versions) and you accidentally press the windows key + enter, you’ll start up Narrator, an accessibility program that reads everything on the screen to you.
To turn it off, press caps lock+escape.
It doesn’t appear that you can turn off the keyboard shortcut :(.
Found here.
If you’re remoting in to a Windows box from a Mac, and using a (fullsize) Mac keyboard, you can accidentally get stuck in overwrite mode (instead of the normal insert mode) when entering text.
This happens because the Mac keyboard does not have a dedicated INSERT button like Windows keyboards do.
The solution is to press CLEAR on the OSX numberpad until you’re sure NUMLOCK is OFF (i.e. you press the numberpad buttons and the cursor moves instead of numbers appearing). Then, you can press the 0 key, which serves as an INSERT replacement (but only when NUMLOCK is off!), to get your cursor back to INSERT mode.
See here for more information about NUMLOCK on a Mac keyboard.
If you’re using a fullsize Mac keyboard, but remoting in to a Windows box, there’s no dedicated NUMLOCK button to turn NUMLOCK on and off. However, there is a CLEAR button which seems to serve the same purpose. If you get stuck with NUMLOCK off, you can press CLEAR to turn it back on. Sometimes you may have to press SHIFT + CLEAR instead.
You’re welcome.
via OSXDaily