Lower case file extension in MS Paint

"The default extensions used in the standard Open/Save dialogs are controlled by each application.

In this case, unfortunately, they are hard-coded inside the MS Paint executable. There's no way to change them, except from hex-editing mspaint.exe (not for the faint of heart).

I would suggest using a file renaming utility to change the letter case of the extensions."

". Right click on the said file
. click on rename
. rename the extension .JPG to .jpg
. refresh the page and yiu should have a lower extension

or

. Open document in paint
. Save as name.jpg in the filename box
. refresh page and you are done"