Disk order keeps changing on reboot.

Hi,
I recently setup Win 7 RC on a machine with 2 internal hard drives. I have windows and a data partition on the first drive (as C and D) and an extra data partition on the 2nd drive (as E).
What I have found is that when I start the machine, the two drives seem to be randomly allocated as disk 0 or disk 1, it is not fixed. When I look at the bios, Sata drive 1 (C & D) is always the first drive and Sata drive 2 (E) is always the second drive (although I then need to reboot after checking the bios, so I can't rule out something strange going on in the bios?)

I have only noticed this because I am also using truecrypt to encrypt the data partitions. Truecrypt seems to get confused by the disk order changing and can't automout the partitions correctly.
Does anyone have any experience of this happening? Why are the two disks not fixed as 0 as 1?

thomas85 said:

Hi,
I recently setup Win 7 RC on a machine with 2 internal hard drives. I have windows and a data partition on the first drive (as C and D) and an extra data partition on the 2nd drive (as E).
What I have found is that when I start the machine, the two drives seem to be randomly allocated as disk 0 or disk 1, it is not fixed. When I look at the bios, Sata drive 1 (C & D) is always the first drive and Sata drive 2 (E) is always the second drive (although I then need to reboot after checking the bios, so I can't rule out something strange going on in the bios?)

I have only noticed this because I am also using truecrypt to encrypt the data partitions. Truecrypt seems to get confused by the disk order changing and can't automout the partitions correctly.
Does anyone have any experience of this happening? Why are the two disks not fixed as 0 as 1?

What are the 2 HD's? sometimes a slow reporting hd can allow another drive to be polled first. We could also use some system specs

Ken

Hi,

Sata Disk 1 is a Western Digital WDC WD6400AAKS 640Gb
Sata Disk 2 is a Seagate Barracuda 7200.10 T3320620AS 320Gb
Motherboard P5B-E Plus, with E6400
Running Win 7 RC 7100
Hope this helps.

thomas85 said:

Hi,

Sata Disk 1 is a Western Digital WDC WD6400AAKS 640Gb
Sata Disk 2 is a Seagate Barracuda 7200.10 T3320620AS 320Gb
Motherboard P5B-E Plus, with E6400
Running Win 7 RC 7100
Hope this helps.

Thomas

I have been thinking. Have you upgraded the mobo bios, and chipset drivers? Is there a setting in bios to order the startup order on sata? I have seen the same thing on a dell that I have. My bios doesn't have the ability to change the specific load order of the sata drives so I was swtuck untill I upgraded the OS to 7600. It might be helpful for you as well

Ken

During the beta, I reported a bug in which the Windows 7 setup program would not enumerate multiple hard drives correctly, a problem that first appeared in Vista w/ integrated SP1. It did not occur in Vista RTM or XP with the exact same hardware. It was not fixed in Win7 RTM, and it's important, because allowing setup to continue can result in it writing boot files to the wrong drive, producing a system that won't boot or worse. My workaround is to open my computer and disconnect all drives but Drive 0 before installing Win7 RTM.

After reconnecting HDs 1 and 2 and booting into the new Win7 RTM installation, I found that Win7 numbered the drives in exact reverse order in Disk Administrator. This was something I had not noticed in the beta, but I didn't investigate it any further after submitting my bug report, and they may well have become reordered on subsequent reboots as you've described. Heck, they may well have become renumbered on subsequent boots into Win7 RTM.

Anyway, I run AHCI, so in my Win7 RTM installation, I went ahead and installed Intel's Matrix Storage Manager, and after rebooting, I found the drives in the correct order in Disk Administrator. I just checked again right now, and yep, they're numbered correctly. So if you have an Intel system, it might be worth looking into the Intel driver. (NB: Installing the driver at setup time did not help with the Win7 beta setup program, and I didn't bother loading it from flash drive when I installed RTM.)

The same thing happens to me but the proper order of the disk is shown after installing the ahci drivers that came with my motherboard