How do i upload my progress on a w.i.p thread

i started a thread in w.i.p but i dont know how to add the blend files as images. i downloaded a screen recorder but it only records and dosent allow me to take snap shots so i can upload those images like i have seen in other w.i.p threads please help.

Windows/Mac/Linux?
Windows you can take a screenshot (in any program) by pressing ‘prt sc’ button (usually to the right of f12) Then open paint or photoshop, etc, and you can paste (ctrl-v) the screenshot. Often times you’ll crop it in the image editor, save it as a jpeg to your hard drive, and then upload it.

You can also take a screenshot from within Blender with Ctrl+F3.