Though there are many ways to protect sensible data but if you are looking for a simpler way then I have found the TweakUI program the best.

Using this program you can hide whole harddisk partition without any efforts. The method is best to use when you have lot of data to protect then what you can do is just copy the data in a drive and hide the complete drive instead of hiding those individually.

To use this program just download this application and run it. You will find a screen shown below.

Now locate My Computer and Expand the + sign, it will display all the disk listed with in windows. Now uncheck the disk which you want to hide… the drive will not be visible any more.

But if you want to access the data back there is not any complexity you only need to use Windows run command (Windows key + R) and give the drive letter and press enter like I have used in the image below..

This will show all data back…. to reverse this tweaking just check the drive again and your disk will again start start displaying.