You cannot paste into the page with right key -------- that won't work here.
It's simple -----
Get a free screen capture thing -- such as
screenhunterAny free screen capture will allow you to capture your screenshot in jpg format - usually the default 'Print screen' key on your PC is used.
* Crop it to look as you wish.
* Then check it is within our upload limits - Max size per file: 250kb. 1800 pixels wide
* Upload it in the 'Upload images' button at the top right of the forums ^^^^^^^ (look)
If you get a problem come back and someone who has done it will help you.
Thanks

Simplicity is the ultimate sophistication. – Leonardo da Vinci