I can tell they're deleted, 'cuz all I can see in the post where you'd placed them is a big white box saying "This file has been moved or deleted."
I knew they were .bmp, 'cuz that's what Paint saves them in by default, and that's what you said you'd made them in.
You need a program made for it to make them transparent. Paint.Net works, as do most. MSPaint won't, though. If you'd rather, you could just assign it a random otherwise-unused color as the background, and I could just edit it out sometime, if I use it.