Microsoft will shortly begin releasing the final build of Windows 8 to MSDN and TechNet subscribers online and thousands of people, including myself will install it and begin using this exciting new OS properly. Are you going to install it on a computer with more than one physical hard disk though? If so, beware drive 0!
When Windows is installed it creates a special boot partition called System Reserved on your computer. This partition, which was 100MB in Windows Vista and Windows 7 but has now been increased in size to 350MB in Windows 8 to accommodate new rescue and boot tools, is always placed on the first physical disk plugged onto your motherboard. This disk is called Drive 0.
It appears in the list of hard disks that you can install Windows 8 onto in the installer, as you can see in this screenshot. The second physical hard disk in your computer will be called Disk 1, the third Disc 2 and so on.
In computers built by Original Equipment Manufacturer (OEM) companies such as Dell, Samsung or HP the current copy of Windows will already be installed on Drive 0 with the System Reserved partition, but if you built your own PC or bought it from a smaller company it may not be.
The problem is caused by the fact that when you’re plugging the SATA hard disk cables into your motherboard there’s usually very little way to know which socket is drive 0. The upshot is more serious however. If the hard disk you want to install Windows 8 onto is actually Drive 1 or Drive 2 then you will never be able to remove the physical Drive 0 hard disk from your computer without rendering your copy of Windows unusable.
Also, if you want to create a system image backup and Disk 0 already has a partition at the beginning of the drive space, the System Reserved files will be placed in this partition. Should this be a large partition containing files for example, then you will also have to include this entire partition and all its contents in your system image backup. This will make for a very large backup file and also restore an earlier copy of all your files when you restore Windows. Wiping out newer files completely.
So how can you avoid these problems? One way is to physically unplug all of the hard disk from your computer other than the one onto which you want to install Windows 8 before you install the OS. This forces the installer to see the only available hard disk as Drive 0, problem solved.
It’s not always possible to physically unplug hard disks however, you might have a twin-hard disk laptop or all-in-one PC for example. Here you need to be careful when choosing where to install Windows 8, to create a drive for it on drive 0 in the disk drives list (when choosing a custom install).
My best advice is to completely delete the existing System Reserved and Windows partitions and have the Windows 8 installer create new ones. This means you will get the maximum benefit brought by new repair feature’s that require the larger 350MB system reserved partition and you will also get around subtle changes that come with Windows 8 installations on newer computers containing UEFI firmware.
Overall though my advice is to take care when installing Windows 8. You might need to wipe some partitions completely and restore everything from a backup after the installation is complete. You do have all your files backed up after all don’t you!?
With Windows 8 installed on Drive 0 in your computer you can be sure you’ll enjoy trouble-free use thereafter, and I sincerely hope you enjoy using Windows 8 as much as I will.