The first thing you do to upload a screenshot is: click on the link it shows when you press F2.
The link is something like This screenshot has been saved as 2016-02-06:...

• After you click on this, it will open up the screenshot.
• If you need to access a different one you took, click open and then photos, and you can scroll along the others.
• You will need to copy or save the shot into your files.
• You can then go to tinypic.com.
• Ignore everything except the red box, where you will click choose file and open up the shot you saved.
• Make sure it is clicked that it is an image, and then hit upload now.

This will give the photo a URL. Then you can open your post, and click the image icon, and paste or type the URL. This will enter the screenshot. If you have any questions or it was not working, either comment here or send me a PM.