My pc was running fine last night and switched off with no problems. I woke up this morning and powered on pc, Windows booted to the start/lock screen and does nothing more. Keyboard and mouse does not respond with the keyboard num lock key lit but you can't switch it off and also there is no mouse cursor. The only hardware change I made to the PC was to install 2 brand new Samsung 250gb 830 series SSD drives and a fresh install of Windows 8. Been using it every day since until now. any ideas?