System HDD is not the same as the W7 installation HDD

Castiel · 3 Jul 2011 at 09:56

As you can see the System partition is on a different HDD from the Windows7 installation.

Does anyone have any idea why?

Also I seem to be having some performance issues on a clean install and wondered if this could be the problem and how to fix it, preferably without formatting and starting again.

Thanks.

Uhtred · 3 Jul 2011 at 10:44

there should be a 'system reserved' partition of about 100mb. I assume you told windows not to do this when you installed?

mrochester · 3 Jul 2011 at 11:23

My first thought is that in the BIOS, disk 2 is set at the highest priority, and thus when Windows 7 is installed, it sees this as the system disk, even if the actual Windows installation is on another drive. My D: drive is the system disk in my PC even though Windows 7 is installed on C:.

Castiel · 3 Jul 2011 at 12:33

Uhtred said:
there should be a 'system reserved' partition of about 100mb. I assume you told windows not to do this when you installed?

I got rid of that when I reinstalled W7 the second time as it was showing as a separate drive, when it didn't before.

d_brennen · 3 Jul 2011 at 12:39

I think the theory is that having the system partition on a separate physical drive might improve performance in some tiny way. I've found the only reliable way to avoid it being on a separate drive is to unplug all storage drives during installation. Not looked into it too much but iirc your system might not boot if you subsequently remove the drive that holds the System partition

Castiel · 3 Jul 2011 at 12:48

mrochester said:
My first thought is that in the BIOS, disk 2 is set at the highest priority, and thus when Windows 7 is installed, it sees this as the system disk, even if the actual Windows installation is on another drive. My D: drive is the system disk in my PC even though Windows 7 is installed on C:.

d_brennen said:
I think the theory is that having the system partition on a separate physical drive might improve performance in some tiny way. I've found the only reliable way to avoid it being on a separate drive is to unplug all storage drives during installation. Not looked into it too much but iirc your system might not boot if you subsequently remove the drive that holds the System partition

I have just changed the boot priority in the BIOS and you are correct, it seems the D: drive has the Boot-mgr and is the first bootable drive, yet the W7 installation itself is on the C: drive.

When I changed the priority so that the C: drive booted first, it wouldn't boot. When I returned the D: drive to boot first then it is fine.

Why would W7 install in this way, and does it have any impact on performance in a negative way, other than not being able to remove the D: drive without rebuilding the boot mgr of course.

bledd · 3 Jul 2011 at 13:33

What you can do to fix it..

Unplug all other hard drives

Turn pc on and insert W7 dvd

Set it to 'repair startup'

mrochester · 3 Jul 2011 at 13:36

Castiel said:
I have just changed the boot priority in the BIOS and you are correct, it seems the D: drive has the Boot-mgr and is the first bootable drive, yet the W7 installation itself is on the C: drive.

When I changed the priority so that the C: drive booted first, it wouldn't boot. When I returned the D: drive to boot first then it is fine.

Why would W7 install in this way, and does it have any impact on performance in a negative way, other than not being able to remove the D: drive without rebuilding the boot mgr of course.

Yes it won't boot if you change the priority of or remove the system disk. It isn't Windows that has installed this way, it's simply a combination of BIOS settings and where you chose to install Windows that's the problem. It doesn't effect performance it simply means if anything happens to the system disk, Windows 7 won't be bootable (although you can probably fix this by running startup repair from the installation DVD).