I have not seen any threads on how to post screenies, so I decided to set one up.
{Step 1: Go to start on your desktop}
{Step 2: Click on the search bar and type run and click enter}
Step 3: When on run Click on the search bar on that and type %appdata% and then click enter
Step 4: This should then show lots of folders find the one that says minecraft and click on it
Step 5: Then when in the minecraft folder find screenshots and open that
Step 6: Select the screenshots you want and then drag them to the desktop
Step 7: Open imgur and if you don't already have an account on it make one
Step 8: upload the images to imgur of you desktop
Step 9: copy and paste the address of your screenie to the image icon on your thread
Step 1 & 2 for windows 8
As you know windows 8 has no start bar so to open run all you do is simply press the windows icon and r on your keyboard on it will open.
When I tried this first my screenies were not images, so what I did was I went to edit and opened my picture in it. Then I re saved my picture as an image. im not sure if this is the same for everyone, but try it if you cant upload it.