Someone once said "If it ain't broke, don't fix it." What's your computer for - processing photos and making prints? Or are you obsessed with having the latest of everything even if it does not improve your photographic work? Ooo ooh, a new iPhone!!
My Win 7 system runs Lightroom, Photoshop, and a few other photo apps fast and totally without errors or crashes. I would upgrade to a new OS because ... why?
Do what's best for you.