There's nothing wrong with mspaint, I do a lot of mouseart with it. To be honest you're being rather vague. What do you need in an image editing program? Because if you want to do more than just resize images and save them in different formats, you're going to have to deal with such "confusing" programs as Photoshop or GIMP. They're not that difficult to learn how to use.
On the other hand, if all you need is to resize and save in different formats, then Irfanview will do you just fine!