For a long time I have save pictures with the dropdown box "save picture as" on my
Desktop. Now for some unexplainable reason (for me, that is) in the box at the bottom
Where it usually says saving as "jpg" it is now saving as "bmp" and that is the last thing
I want. Then it comes up on Adobe which I used to use but not anymore. I tried to
Delete it and put jpg in but I can't. Help!

JPG or JPEG stands for "Joint Photographic Experts Group". It's a compressed format. BMP stands for "Bitmap" and is not compressed.

I'm not sure what you mean by "Adobe". There are many Adobe programs: Adobe Photoshop, Adobe Photoshop Elements, Adobe Acrobat, etc.

Try this. Select FILE | NEW to create a new image. Select FILE | SAVE AS. In the drop-down box, that's probably labeled "FORMAT", select "jpg" and save it. (You can then delete it because it won't be useful to you). I think that the save dialog will default to JPG from then on.