Just bought a new 500GB HDD for my MacBook and did a fresh install of Snow Leopard and the OS keeps freezing randomly. It doesn't crash, it just freezes for a second and then carries on. It happens no matter what program I am using. Even as I am typing this it stops and then all my letters appear on screen all at once. Strange thing is, any music carries on playing fine and my cursor still moves around the screen without stopping. But if I'm watching a video, scrolling down a page, or typing, it will stop for a second for two and then be fine again. It didn't bother be at first but now I know it's happening it is getting really irritating. Would another fresh install fix this or could it be a problem with my MacBook for the new hard drive? EDIT: One particular thing it does this is VERY often is Flash videos. I know Flash generally sucks for OSX but I've never had it do that. But the problem still occurs when Flash is not being used.