Are you a Vista user who also wants to run the Windows 7 OS?  Let me tell you, installing Windows 7 on another drive on your system would crop up a mess. I did the same with my dual boot laptop and to my utter dismay, the partition of the other operating system (Vista in my case) was not showing. The next moment I was searching for ideas to fix the error message because I was sure that Windows 7 was installed correctly in some other drives. I found a solution. If you faced similar kind of problems. I'll share the trick with you to take you out of this misery.

Here's what you need to did to get rid of the problem

Step 1

Click on the Windows key. Enter diskmgmt.msc and press enter. The Disk Management interface opens. It give you the details of hard drives and partitions. Search for the missing drive letter

Step 2

Select the partition with the missing drive letter in the lower half of the screen (look for the Disk 0, Disk 1, etc.) and right-click.

Step 3

Select the Path and Change Drive Letter from the context menu. Now click on the Add button in the next menu. Choose a drive letter from the pulldown menu.

Finally a click on Ok and you are done. So yo can see the Windows Vista partition or any other missing partition in the Windows Explorer.

[Source: Windows7news.com]