X:\ is not accessible. The media is write protected [Solved]
While trying to mount an image in OSFMount you might get this error from the operating system.
X:\ is not accessible.
The media is write protected
With X: being the drive you are trying to mount.
In most cases it is possible to mount NTFS drives as a read only devices ,except in old versions of Windows like Windows 2000. But in some case it seems Windows throws the error above if an image is mounted with the read only check box set, AND the image came from a different machine.
For example we saw the problem mounting an image in Win7 of the boot drive from an old XP machine.
The solution to the problem seems to be to allow both reading and writing to the image when initially mounted on a new machine. After the initial mount as a R/W device, you can then immediately dismount the drive and re-mount it as read only.
Poking around in at a deeper level it seems that Win7 wants to make an update to the "$Secure" file during the first mounting of the image. $Secure is a hidden NTFS file in the file system with the Access control list (ACL) database. So maybe it is adding a SID (Security Identifier) to the ACL for the new machine? If anyone knows the exact details feel free to post them.