I have Windows 8.1 Pro (x64) installed on Alienware M17x. The slowdown mostly appears as slow response in the situation such as open a folder/window, open/close/switch tabs in IE, drag window, and there's also cursor lag. It gradually slows down after system boot, noticeable after 3-4 hours, really slow after 8-9 hours.
I have thought about many possible processes which can cause this issue, and then I found out that it's caused by "explorer.exe". If I kill "explorer.exe", the speed suddenly becomes normal. Then, I restart explorer.exe again, it stays normal, and then it still gradually slows down again after hours.
I have checked driver or software compatibility. Also, CPU usage and Disk usage is normal.
Please give some advises, reasoning, or solutions.