Everything lags on my kids pc. its a Dell Core2Duo, not an amazing system but my kids like to sit & watch funny youtube video's & stuff. Its got a HD3780 GPU in & everything is dust free as I clean it often. I have no idea why it's doing it or what could be causing it. When I say everything lags I mean everything, the mouse cursor, videos playing & music. I recorded a minute of it happening so you can see what I mean. Advice would be great as I'm not an intel fan & this problem has only happened on Intel systems for me. It's got plenty of memory & HDD space & the browser is not lagging as its memory usage is low. I don't know if its getting to hot, would heat cause this?