You would need to use software like MS Paint, Photoshop, or another image manipulation program *See Below*. Typically there is an option to resize/scale the image you want to use, and in doing so, you specify the size.
The size of the avatars on the forum is rather small, 90 pixels square, and less than 6 kilobytes in filesize - so you *really* have to shrink down the image.
There is an online photo editor that allows you to upload and edit a photo, and then save to your computer - without having to get into installing specific software if you don't have it.
Pixlr Photo Editor:http://pixlr.com/editor/
- When you arrive at the site, select "Open image from computer" - and then navigate to the photo you wish to use.
- You can also choose "Open image from URL" and then provide a link to a photo. (flickr, imgur, photobucket, etc.)
That will open the image in the online editor.
- From there, click on "Image --> Image Size" at the top of the browser.
- Change the dimensions to 90 and 90; you will need to un-check Constrain Proportions, unless you're using a square image.
- Click "OK" and congrats! A Tiny image.
- Next, click "File --> Save", leave it set to the "My Computer" tab, and give it a name. It tells you here what the size of the image is, so, if it's larger than 6K, you'll need to shrink it down more or turn the quality down a bit which will reduce size.
- Once it's good to go, click OK. Remember where you save it, and then when editing your profile, choose that image to upload.
We can probably make the restrictions a little less severe with regards to file size - but I think keeping them small in dimension is best. If you need help, let me know!