I signed up for
www.windowslivephoto.com IT'S FREE! I download my pictures to window live photo. Then I go to reply to thread and at the bottom of posting I click on go advance. I then fill in the title and go down and add my message.
Then 2 lines up in the fourth lit bar there are 4 icons. Click on #3 the frames that has a tree in it.
It will come up with how you want to get pictures and click on computer then browse. Pick you picture and open. It will take you back to window and click upload and it will open your picture just below your message area. The picture will be small. Just double click on it and choose full size and you picture will be the right size.
I find the windows live photo will make the picture the right size to upload.
Hope this helps you.