I have successfully edited the registry in other Windows operating systems to make other specified partitions on my pc inaccessible by that operating system. I'm referring to the mounted devices offline /dosdevices/d: keyword. When I add the offline key and 32 bit dword /dosdevices/d: for Vista the drive named in dosdevices/d: remains online. Am I doing something wrong or is there another way to set volumes offline in Vista. I am trying to avoid the deletion of system restore points in Windows 8. I am not sure but am trying to rule out Vista as causing the deletion. Thanks in advance for any comments.