el-capitan

I have the following problem: My 2016 Macbook Pro (El Capitan) hangs on boot. The progress bar loads to near completion, after that it stops. The laptop heats up and eventually shuts down. What I need to do: Recover important data from the partition, then reinstall. No time machine saves are...

Hey guys, I've just bought the Macbook Pro 13" 2015 with Retina-Display and macOS Sierra as operating system installed. I'm really glad to have it now but I didn't expect to have UILags so now, I know it isn't the performances fault. Is this problem to fix? Yes? How? No? What should I do...