To add to what MSmariosonic is saying, I think you have to wait a bit to become able to post images from your hard drive, not sure what the trigger is though (I think you have to make more than 10 posts or something?).
I myself had to go to
Forum Support and ask an Admin to enable Image Uploading for me (after 10 days of waiting for it to activate), I'm not sure if this is a common issue or not, but if you go a while without seeing the "Attach Files" in the bottom left of the posting area (and get error messages when you do it through the "Insert Image" button MS circled in his post), you'll have to do what I did.
With that said, Welcome to the Boards.