Why all drives are converting to dynamic when I created one

Question

I just installed Windows 7 Ultimate on my new Lenovo G570 laptop. I left some unallocated space so as to create few dynamic drives as there is a limit for primary.

So, when I created a dynamic drive from unallocated space, windows changed all drive from primary to dynamic including the drive which contains OS. Thus when I rebooted my system, windows couldn't start.

Why this is happening, is there any problem with my PC?

Answer 1

The major problem lies in your understanding of the concepts.

• Partitions may be primary or secondary in the old PC/AT (a.k.a. "MBR" or "MS-DOS") partitioning scheme. (In the new EFI partitioning scheme, there's no such distinction and no need for such a distinction.)

  Secondary partitions live within container (primary) partitions. Sometimes — and somewhat confusingly — they are known as logical drives and the container partitions as extended partitions.

• Discs may be dynamic or basic.

  Basic discs use the partitioning scheme (be it PC/AT or EFI) as-is. Dynamic discs overlay that with a Microsoft proprietary logical volume management system.

You've converted a basic disc to a dynamic disc when what you actually wanted to do was create a container partition with some secondary partitions in it because you'd hit the four primary partition limit of the old-style partitioning scheme. To get where you originally wanted to go, you'll need to convert your dynamic disc back to being a basic disc once more, and create secondary partitions in a container partition instead.

My educated guess, given that you've provided nowhere near enough information for diagnosis, is that Windows will not boot probably because you've changed the identity of your boot volume. But the only Microsoft-sanctioned conversion method from dynamic to basic involves wiping your entire disc and starting again. So fixing the problems with booting is pointless. You'll be wiping and reinstalling anyway.

Yes, some people will say that they've hand-edited their old-style partition table with a hex editor to convert a dynamic disc back to a basic disc. This will only work in a quite limited range of circumstances, and mess things up quite royally the rest of the time. It's not something that I'd recommend to someone who hasn't yet got primary/secondary versus dynamic/basic straight. ☺

Further reading

• Microsoft corporation (2000). Basic and Dynamic Discs. TechNet.
• Microsoft corporation (2007-12-01). Basic Storage Versus Dynamic Storage in Windows XP. ID 314343. Microsoft Support KnowledgBase.
• Microsoft corporation (2004-07-14). How To Convert to Basic and Dynamic Disks in Windows XP Professional. ID 309044. Microsoft Support KnowledgBase.
• Microsoft corporation (2005-01-21). Dynamic disks and volumes. TechNet.
• Microsoft corporation (2005-01-21). Change a dynamic disk back to a basic disk. TechNet.