Ok. I'll walk you through all the steps once more, hopefully it will work for you then.
Uploading an avatar picture should be quite simple, especially if you upload them from your computer.
First, you have to make sure that your picture isn't too big (both in dimension and file size).
Open Paint and load the image you wish to use.
Select the area you want to show on your avatar image using the selection tools.
Use the cut function to discard everything but your selection.
Now, I do not know how well our forum's avatar function scales an image down. So even if you cropped your image, it may still be to big. What you can do is scale your image down a bit (say to 50%). The image you upload can be bigger than the forum avatars, our forum will scale it down, but it can't scale huge images. I'm guessing if you go for 200x200 pixels it'll be fine for sure. Note: this are two different things. Cropping is selecting a certain area of a bigger image, scaling is making the same image smaller.
When you have an image that's of reasonable size, save it to a location on your computer. Then go to your profile page and upload the image from your machine and click accept.
I really hope it will work like this for you. But like Pam already said, at some point it becomes hard to help when you can't see where it's going wrong.
