To Disable write caching to disk , follow these simple instructions

1) go to start menu, right click my computer and select properties
Start-right click my comp.

2) you will get a dialog box, select the hardware tab then the device manager button.
system properties

3) expand the “Disk Drive” Category, and select properties.
Disk Drive Properties

4)Select the policies tab
Policies Tab

5)untick “enable write caching on the disk” then reboot your machine.