Looool, just a note, this might not work if you use a laptop..How are you on your computer may I ask?
Press the key near the top right of the keyboard that says 'Print Screen' or 'Prnt Scrn' when you are on the screen you want to take a screenshot of, then open up any image editing software and makesure its a new document, then press either 'Ctrl + V' or go to 'Edit' then 'Paste'. You can then save this image and upload it to anywhere you wish, i.e.You must be registered for see links
It's next to 'Insert' on my keyboard:Here's a easy summary;
1. - Press Print Screen SysRq next to "Scroll Lock"
2. - Go to paint or w.e
3. - Ctrl + v or Edit and Paste.