Fix It: New Hard Disk volume becomes inaccessible after a power loss
In Windows 7, you create a new simple volume in Disk Management or DiskPart.exe on a non-removable disk. If your Windows 7 system experiences a sudden power loss within a few minutes of volume creation, you may notice the volume you created before the power loss is inaccessible and is not assigned a drive letter when you power the system back on.
Also in Disk Management the volume may not have a status (for example, "Healthy") or a file system type listed. If you try to modify the volume in Disk Management, you may receive the following error message:
The operation failed to complete because the Disk Management console view is not up-to-date. Refresh the view by using the refresh task. If the problem persists close the Disk Management Console, then restart Disk Management or restart the computer.
Download Fix It from KB2001877 to fix this problem.