Have three laptops. Oldest is a retired Dell now relegated to running my Davis weather station and webcam. It's XP operating system is the most reliable and stable. Dang thing is just too big and heavy to carry around. Newest Dell running Windows 7 is least reliable. Just returned a Dell Windows 8.1 to Best Buy that died after a week. Had enough time to play with it to tell that while the Windows 8.1 touch screen is a steep learning curve, it seemed stable. 8.1 is a huge/complex operating system requiring a lot of resources e.g. i5 or i7 processor and 6 to 8 gigs of memory.