yes of course, but there does come a point when it's not worth it to do it. I have lower grades from my freshman year from a couple of years ago so I'm waiting until I'm done all my summer courses for those grades to help boost my overall gpa. But if I had a good gpa and I was just trying to 'pad' it. I think there comes a point when it's a waste of effort and money and sometimes, depending on how many courses you've taken, it's inconsequential.