For years, desktop publishers have asked their clients to save their pictures and their images as separate files. For example, if you're a freelance writer, you may have noticed that most magazines always tell writers to submit photographs or other images separately from their articles. There's a reason for that. Desktop publishing software needs to have words and images as separate files so they can be assembled into a layout, such as a magazine page. DTP software can't import complex Word files correctly, so a lot of author formatting goes away. (I've often thought about how much time is wasted by authors trying to "pretty up" their files.)
Of course, I've been an editor for many years, so I have spent more than my fair share of time attempting to extract pictures out of Word files from those people who did not follow the instructions. It can be a huge pain to get graphics back out after they've been pasted into Word. Many times the image quality suffers, but sometimes if you are lucky, you can extract them.
Depending on the type of graphic file and how the writer embedded the files in Word in the first place, sometimes it's relatively easy to just select the picture and press Ctrl+C to copy it to the clipboard. Then you can paste the image into a graphic program and save the file separately.
Another thing that sometimes works is pasting the file into PowerPoint. Then you can right-click and choose Save as picture. The resulting file's resolution is dependent on the original file's resolution when it was embedded in Word, not on its scaled size. So sometimes you can get a better quality file that way, especially if the original was a vector line art image (as opposed to a bitmap).
If the pictures are screen captures or other low-resolution bitmaps, one sneaky way to get around the problem is to try saving the file as HTML. Choose File, Save As and change the Save As Type drop down to Web page (*.htm, *.html). When you do the save as, Word creates GIF or JPG files of all the graphics. Although the image quality is only screen resolution, this method is by far, the fastest way I've found of saving graphics as files when they've been embedded in a Word doc. If you have a manual with 200 screen captures that need to be extracted, it's certainly worth a try.