System using 50MB/s of the hard drive.

Hello, since I put my computer to sleep an hour ago, it is very, very slow (the mouse is struggling) I went to the task manager and there is 100% disk usage, I looked at what is using it, the application "System" is using about 50MB/s (98%) but when I launch Google Chrome (and stay on it) system drops to 0.1MB/s and 0% usage.

Have you ever had this issue? What do you recommend?

P.S. I'm using Windows 8.1 64-bit and I haven't had any problems until now.

Thanks in advance for taking the time to read this.