How to make drive C as Disk 0

gilloz · 18 Apr 2014

I assumed that the Disk numbers shown under Disk Management would show up as Drive C= Disk 0, Drive D= Disk 1 and Drive E would = Disk 2. I have the main system drive C and two storage drives D&E. When I went into the installation of a dual boot system with Ubuntu partitioned on the Drive C, it came out, under the Terminal in Ubuntu as sdb1 instead of what I expected to be sda. Going back to Windows 7, sure enough, Drive E= Disk 0, Drive C= Disk 1 and Drive D= Disk 2. I was trying to load the Grub boot loader in the sda drive, not the sdb drive. My workaround was to disable Drive E which caused Drive C to indicate Disk 0 in Windows and drive sda in Ubuntu. I loaded my Grub2 boot loader into sda and it all worked out fine. My dual boot works good, but reconnecting Drive E back, made it go back to Disk 0 under Disk Management. Why doesn't the system recognize Drive C as Disk 0?

gregrocker · 18 Apr 2014

It is normally determined by which mobo port you use, but can also vary as discussed here: OS disk not disk 0 - Windows 7 Help Forums

If you want to post back a screenshot of Disk Management - Post a Screen Capture Image we can look it over for you. But since your using GRUB to manage the boot, the normal concerns would not apply: the System Active partition booting Windows should be first in order to avoid during repairs or reinstall derailing the boot files to a preceding Primary partition - which can also be achieved if necessary by converting preceding Primary to Logical partitions which cannot receive boot files.

whs · 18 Apr 2014

Disk numbers are one thing. They go by the ports on the mobo. Drive letters are not for disks but for partitions or devices like optical drives or USB flash drives. Except for C (and A and B which are reserved for floppies) the drive letter assignment is pretty random. It is first come first served.

And you can have many partitions on a disk. If disk0 has 5 partitions, disk1 may have drive letter L for the first partition because F may be a USB stick, etc. And C may be on disk2 or 3 because that's how you wired the disk where you installed the OS.

Bottom line - it makes no sense to develop theories about partition lettering. Any combination is possible. Only A,B and C have a special meaning - and even then you can have an OS partition that is not C - if not active.

And if you want to get really confused, read this: https://neosmart.net/wiki/easybcd/dr...-disk-numbers/

gregrocker · 18 Apr 2014

But don't try changing the OS drive letter. It will ruin the OS beyond repair. Any other letter above C can be changed in Disk Mgmt: Drive Letter - Add, Change, or Remove in Windows 7 - Windows 7 Forums

AddRAM · 18 Apr 2014

The best you can do is put the hard drive with the operating system on port #1 on the motherboard.

gilloz · 18 Apr 2014

OK, thanks guys for your responses. I'm going to look at this information and digest it for a while. In the meantime, I will do nothing because everything appears to be working fine. I just didn't get the labeling of these disk in Disk Management. Thanks again.