Depends on how big the file is. the maximum size can not be higher than 262kb. Other wise it will just not upload. And as for your other thread the reason why your image is not showing from the [IMG] link is because you have to upload it to an image hosting site.
Image Thrust
This site is awesome for hosting 1.5 mb or lesser sized images. Make sure to make a username or your images will not be findable.