How can I upload a better picture?

I know .bmp’s aren’t “supported” (even though I was using them just fine before 3.7.1)… but every other type of file that I can upload are way to small of pictures (.jpg’s, .png’s…). I am using microsoft paint to make my pictures… there has to be an easier way to upload higher quality pictures besides .bmp’s that will work.

I can upload all media just fine, but when I try to insert it into the post, .bmp’s don’t work. I can put my type cursor to a place where the picture should be, and both the link/ unlink buttons activate… but no picture.

So I don’t know. I’m an idiot. I’m sorry. I am just desparate for help.

Thanks