Hiding Disk Drive in Windows

On the computer I use, I installed two hard drives. In each of these disks I use the Windows XP operating system. Usually, to determine which operating system will I enter, I use a boot loader software. Which is a problem, when we boot the hard drive to hard drive first, hard disk drives both still appear as a drive D:\. Well, how do when we boot to the hard drive first, second hard drive is hidden, and vice versa. When booting to a second hard disk, the first hard drive hidden?

Answer:
There are two ways to do this. The first way is the manual way, while the latter is more useful when you do not want to bother to change the settings every time needed.

The first method by selecting the option to disable hard disk you do not want access through the BIOS. In this way, the drive was not accessible not only hidden by the operating system, but the total disabled access.

The second method is to disable the drive from the operating system. How, go to the registry and locate the following entry:
HKEY_CURRENT USER-Software-Microsoft-Windows-Current Version-Policies-Explorer. In the right pane, right-click and select Edit> New> DWORD Value. After that create new value with the name NoDrives. Double click on the entry and give the numbers 1 to hide drive A, 2 for B, 4 for C, 8 to drive D, E 16 to drive and so on.