You receive a "STOP: 0x00000050" error message when you start a Windows Server 2003-based computer by using the iSCSI Boot Initiator

Consider the following scenario:

• You enable the Driver Verifier tool on a Windows Server 2003-based computer, and then you use the tool to verify the Iscsibp.sys iSCSI driver.
• The computer starts by using version 2.07 of the Microsoft iSCSI Boot Initiator driver or an earlier version.
• The MmMapIoSpace function is called.

In this scenario, you receive a Stop error message that resembles the following: Additionally, the System log records an event that resembles the following:

Date: date
Source: System Error
Time: time
Category: (102)
Type: Error
Event ID: 1003
Description: Error code 00000050, parameter1 0xeb7ff002, parameter2 0x00000000, parameter3 0x8054af32, parameter4 0x00000001. For more information, see Help and Support Center at http://support.microsoft.com. Data: 0000: 53 79 73 74 65 6d 20 45 System E 0008: 72 72 6f 72 20 20 45 72 rror Er 0010: 72 6f 72 20 63 6f 64 65 ror code 0018: 20 30 30 30 30 30 30 35 00000MN 0020: 30 20 20 50 61 72 61 6d 0 Param 0028: 65 74 65 72 73 20 66 66 eters ff 0030: 66 66 66 66 64 31 2c

Note The symptoms of a Stop error vary depending on the system failure options that are configured on the computer. For more information about how to configure system failure options, click the following article number to view the article in the Microsoft Knowledge Base:

This problem occurs because the iSCSI Boot Initiator driver (Iscsibp.sys) maps RAM memory ranges incorrectly as ROM memory.

Note Not all "STOP: 0x00000050" errors occur for this reason.

To work around this problem, disable the Driver Verifier tool for the Iscsibp.sys driver. To do this, use the following methods in the order in which they are presented.

Method 1: Use the "Last Known Good Configuration" feature

Start the computer by using the "Last Known Good Configuration" feature. For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:

Method 2: Use the Recovery Console

Use the Windows Server 2003 CD to restart the computer. Then, use the Recovery Console to disable the Driver Verifier tool in the registry. To do this, follow these steps:

1. Configure the computer to start from the CD or DVD drive. For more information about how to do this, see the computer documentation, or contact the computer manufacturer.
2. Insert the Windows Server 2003 CD in the CD drive or in the DVD drive, and then restart the computer.
   
   Note If you are prompted, click to select any options that are required to start the computer from the drive.
3. When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
4. If you have a dual-boot computer or a multiple-boot computer, select the installation that you want to access from the Recovery Console.
5. When you are prompted, type the administrator password.
   
   Note Press ENTER if the administrator password is blank.
6. At the Recovery Console command prompt, type the following commands. Press ENTER after each command.
   cd system32\config
   ren system system.old
   ren software software.old
   ren SAM SAM.old
   ren security security.old
   ren default default.old
   cd \
   cd windows\repair
   copy system C:\windows\system32\config\system
   copy software C:\windows\system32\config\software
   copy sam C:\windows\system32\config\sam
   copy security C:\windows\system32\config\security
   copy default C:\windows\system32\config\default
   Important The Repair directory contains a copy of the registry that represents one of the following states:
   • The first time that the system successfully started after the operating system was installed
   • The last time that you performed a full system state backup
   Any changes that you made to the computer since the repair copy of the registry was created will be lost. This procedure resets your password to the password that was used in the following circumstances:
   • When you first installed Windows Server 2003
   • When you last backed up the system state
7. To exit the Recovery Console and to restart the computer, type exit at the Recovery Console command prompt, and then press ENTER.

For more information about how to use the Recovery Console, click the following article number to view the article in the Microsoft Knowledge Base:
For more information about the Driver Verifier tool, click the following article number to view the article in the Microsoft Knowledge Base:

This problem is scheduled to be resolved in a future release of the Microsoft iSCSI Boot Initiator. Microsoft is researching this problem and will post more information in this article when the information becomes available.

The following factors directly influence the frequency of occurrence of this issue:

• The Page Frame Number (PFN) database structure is sparse.
• RAM mapping exists between physical address 512KB and physical address 1024KB.

This problem occurs with more frequency on the computers when the Driver Verifier tool is enabled. The Driver Verifier tool does not allow for the allocation of large pages for the PFN database. Therefore, the chances of a sparse PFN database increases.

The Driver Verifier tool is included with the operating system.