Don't Know Why

OldMX said:

Good info, but how you changed signatures, etc? My wife's computer has exactly the same issue, and i dont know how to fix it

This has been a problem stated in this forum and outside for some time. Changing disk signatures is easy. But I'd hold off on this for a while.

I'm waiting for some feedback on what I'm putting forward.

mjf: I will grant you the fact that this is what and how the system is supposed to operate. However, can you explain two things.
1. If a drive is the only one in the system, and that drive is 'Primary, Active" and then another drive is introduced, this drive simply formatted and a data disk, why would it knock Disk 0 to disk 1? Is it because of the registry? Or is it the formatting? How Can I read this code in the MBR on the disk and match it to the data in the registry?
2. You said that " Disk 0 is on SATA Port 6 and Disk 1 is on SATA port 1", where can I find this information? Is there something that will tell me how my SATA ports are set up or do I go by the manufacturer?

I have tried to stress that I am feeling my way on this matter in the absence of appropriate reference material or input from others.

In terms of sata ports or channel numbers you can simply go
computer > right click a disk partition> select hardware tab
you will see the channel numbers for the sata devices.
It appears that the OS disk numbers are assigned in the registry. Here disk numbers are assigned to disk signatures. The OS disk numbers are not the same as the port or channel numbers. See my screen shot.

1) for a drive to be bumped by a "new" data disk from 0 to number 1 position, I believe the data disk must have an existing disk signature that is associated with disk number 0. Formatting will not wipe the disk signature. Windows will assign a disk signature if it initializes the disk and creates an MBR.
One of my screenshots show the location of the disk signature in the MBR which can be viewed with a Hex editor or from an elevated command prompt type
>diskpart
>list disk
..........the numbers of your disks are listed
> select disk n
.....n=0, 1, etc
>uniqueid disk
....will list the hex disk signature in the MBR
>exit

2)My reference to sata port 1 and 6 was just MY setup. My port 1 (channel 0
is a sata/6 so I have my Windows disk number 0 associated with the disk signature of my boot disk which is physically connected to my sata/3G port 6.
Phew!!!!
--------------------------------------
So look at the disk signature of the disk which insists on taking the 0 place then look at the registry.

I understood that you were giving your perspective as at how things worked, I happened to find a post from 2003 that basically said the same thing, only the guy giving the information was from Microsoft (I believe) and in a heck of a lot more detail, about 3 pages worth.
In regards to the SATA port numbering, I kinda figured that your motherboard was set up that way. Not all motherboards are set up the same. On my MB I have 6 ports in sets of 2, DISK 0 being the first and so on. Whats weird though is that if I place Disk 1 next to Disk 0, the way it's supposed to be according to the manufacturer, it will knock Disk 0 out of it's position. I even used DISKPART to clean the drive and that didn't work. My solution was to put DISK 1 where DISK 2 should be and everything fell into place. Why? I have no idea.
I am not a computer wiz but I do learn quickly and I'm glad you listed how to find the information and I'm gonna do just that.

treadhead194 said:

I understood that you were giving your perspective as at how things worked, I happened to find a post from 2003 that basically said the same thing, only the guy giving the information was from Microsoft (I believe) and in a heck of a lot more detail, about 3 pages worth.

I'd like to read it, can you give the reference please.

If I can find it again

[URL="[URL="http://www.pcreview.co.uk/forums/does-active-partition-mean-t1489512.html"]

This may tie in with this theory by one of the moderators
Diskpart / Disk Management vs the BIOS

Maybe the role of the registry entry is mainly avoiding disk clashes (uses disk signature).