Go to:

Tools > Options > View (tab)

Make sure that in the Show group you have 'Picture placeholders' unchecked and in the Print and Web Layout options group you have 'Drawings' checked.

If these options are set and you STILL can't see the pictures, then the issue is with your display driver and you should see if there is an update, or if you are using the generic Windows driver, go search for one for your make and model of monitor.

Let me know if this fix works for you - I've come across this a few times now - and one of the two options has always fixed it (so far!).