1:
Print Screen key on your keyboard- On my keyboard, it is sitting to the right of my F-12 key, along with Scroll Lock and Pause/Break. Some keyboards place it with the Home and End Keys.
Then, once you've pushed the "Print Screen" key (also labelled "SysRq" LONG story behind that one...) open Paint, and use Edit->Paste. You can then perform a File->Save to save the file as a GIF or JPG.
Once this is done, you need to upload the picture to a file hosting site- I use Photobucket, ImageShack and a few others are just as good.
Once you've uploaded an image, most uploading services will provide you with the IMG forum code so you can paste it into your reply. Hope this helps you!
