The PNP algorithms that are used by Windows Server 2003 and Windows XP for PNP enumeration are optimized by using an in-place reorder mechanism. The last item that is detected can be listed first. As a result, when you run Windows Server 2003 Setup or Windows XP Setup on a computer with two hard disk controllers, where each hard disk is configured as master, Setup can list the hard disk that is configured as master on the secondary controller first in the list of available hard disk drives for the installation of the operating system to that hard disk.
This behavior can occur on computers that are running Windows Server 2003, Windows XP, and earlier versions of Windows. PNP enumeration and the order of the hard disks that Setup detects is not guaranteed. Note the following considerations that apply to the differences in PNP enumeration behavior in Windows 2000, Windows Server 2003, and Windows XP:
- In Windows 2000, PnP processes its array of requests and moves the hard disk drives that it is going to start first to a separate array.
- Windows Server 2003 and Windows XP perform an in-place reorder operation to optimize PnP. As a result of the reorder operation, Windows Server 2003 and Windows XP may enumerate the hard disk on the secondary IDE channel before the hard disk on the primary IDE channel. The hard disk that Setup detects last is listed first.
The PNP enumeration behavior in Windows Server 2003 and Windows XP applies to the whole operating system and is not limited to computers with two hard disk controllers, as described in the example earlier in this article. For example, this behavior can occur on computers that have multiple logical disks on one Small Computer System Interface (SCSI) hard disk controller or on computers that have multiple network adapters that use the same driver.
For additional information about related topics, click the following article number to view the article in the Microsoft Knowledge Base:823206 Unexpected relationship is identified between Device Manager and the local area connections
Note During the text mode Setup of Windows Server 2003, if one of the attached drives is a removable disk drive that contains no media, the empty removable drive is treated as if it has a single logical partition. This drive is assigned a drive letter. If another drive that contains an active primary partition is not found, the removable drive may be assigned drive letter C. To prevent this, make sure that another drive in the system contains an active primary partition. If you use Windows Preinstallation Environment (Windows PE) to start Windows Setup, you can use the Diskpart utility to create partitions before you run Setup.
Article ID: 825668 - Last Review: Mar 29, 2017 - Revision: 4