A Dell XPS laptop or desktop? First of all, you cannot boot and it freezes. Most probably a hardware problem. Re-inserting and cleaning the slot for RAM(memory). Since it may be old, When was it last blown out from dirt or dust? Make sure also that the battery(CMOS,3V)still has that usable power to boot your CPU. After all, an 8 year computer would be worth the maintenance check-up. When it boots to desktop normally, post for another topic here when it comes to computer lags issue.