The keyword to my question i "paste", not "save".
My company uses a tool that will evaluate the Word documents we made, and one of the criteria is all the images must be in JPG. Regardless of what 3rd party screenshot I used (Lightshot, Greenshot, ShareX, Skitch), the pictures will always be pasted as PNG in Word. The tools have setting to save the image as JPG, but only for save, not copy to clipboard as JPG. This means whenever I paste an image from screenshot, it will be pasted as PNG, then I have to cut and paste special as JPG. Problem is most of my screenshots involves small details, and when cutting and pasting from an already pasted image, the resolution becomes significantly worse. I tried the "do not compress" and "high fidelity" options in Word, but no improvement in image quality.
So the only option I can think of is making sure when an image is copied into clipboard, it is already in JPG, so I don't have to repaste the image. Can anyone help guide me on how to do this?
Edit: So I found out that regardless of what image type you copy on, Word will always paste it as PNG. To convert it to JPG, you have to cut from the already pasted image in Word, and paste it again as JPG, which resulted is significant loss in quality. It seems it depends on the source of the image you copied from, where if Word doesn't recognize it, you can only paste in the default image format. If I can somehow change the default paste format in the registry that would be great.