Angus Kidman28 September 2006, 12:27 AM
Microsoft has grudgingly given some ground to critics of its 'nuke-first-ask-questions-later' approach to master boot records in Vista, but will it be enough to satisfy users who want to run more than one OS?
While Microsoft would like the world to believe that anyone running Windows has no need of any other operating system, that attitude doesn't cut much mustard with many of its users.
Why settle for one OS when your PC is easily capable of running two or more?
Users who want to run Windows alongside (say) a flavour or two of Linux will typically end up with a customised master boot record (MBR). The default MBR on a typical Windows PC automatically passes control to Windows on booting, but a modified MBR can allow you to make your own selection.
PC manufacturers also often alter the MBR to allow their own diagnostic and recovery tools to run in the event of system problems, a process that is often triggered by pressing a specific key during booting.
One of the more questionable tactics that Microsoft has implemented in Vista is to automatically overwrite any existing MBR during the installation process without asking if you mind or giving you an option to back up.
Microsoft says that the Windows installation system can't intelligently interrogate an existing non-MS MBR, although such features are quite common in the install routine for other OSes.
It also argues that an "official" Vista MBR is required for security features -- such as measured boot, which works with Trusted Platform Module (TPM)-enabled chips to check that the OS hasn't been hacked or altered each time it boots -- to work correctly.
While Microsoft is continuing to maintain its nuke-first-ask-questions-later approach to the MBR, it has thrown a small scrap of comfort to software developers who have written diagnostic tools that create their own MBR.
New documentation on Microsoft's Vista site explains how manufacturers can install their own custom diagnostic tools inside the Vista MBR.
"It is clear that manufacturers are making use of custom MBRs to deliver value-added experiences to their customers," the white paper notes. "As a result, Microsoft has developed a feature in Windows Vista that enables OEMs to customise their platforms without having to introduce custom logic in the MBR header."
This shouldn't be mistaken for a full-blown smorgasbord of boot choice options. In the current build of Vista, the only option available to developers is to launch a specific boot application in response to a defined keystroke. Dell could launch a hardware test utility, for example, if you held down "T" on bootup. Microsoft says it may offer other options and input types in future versions of Vista (not one to hold your breath for, we suspect).
Because the Windows Boot Manager still has to load before the new custom boot applications can be detected and launched, this doesn't seem the ideal way to launch a menu system for choosing between OSes. However, a little developer ingenuity might solve that problem in the near future, even if it creates an MBR which, as Microsoft sniffily puts it, "cannot be cleanly integrated with system recovery".