Network performance is slow when you run Windows Preinstallation Environment 2.x in certain hardware configurations

When Windows Preinstallation Environment (PE) 2.x is running in the following hardware configurations, you experience slow network performance:

• On a system that has a Broadcom NetXtreme Gigabit Ethernet controller that uses ASIC version BCM5704 B0
• On a system that has more than two Intel Extended Memory 64 Technology (EM64T) processors installed

Note The following computers are affected by this issue:

• Dell PowerEdge 6850
• IBM xSeries 3850

To work around this issue, follow these steps:

1. Disable hyperthreading in the computer's BIOS.
2. Modify the Boot Configuration Data (BCD) store in Windows PE 2.x so that only one CPU is visible to the operating system. To do this, follow these steps:
   1. Start Windows PE 2.x.
   2. At a command prompt, type the following command, and then press ENTER:
      bcdedit /store Path /set {default} onecpu on
      Note The Path placeholder represents the path of the BCD store. By default, the BCD store resides in the following location:
      c:\winpe\iso\boot\bcd folder in Windows PE 2.x

This issue does not occur if one or more of the following conditions are true:

• The computer has a Broadcom NetXtreme 1 Ethernet controller installed that uses a version of ASIC other than BCM5704 B0.
• The computer is equipped with non-Intel EM64T processors.
• Windows PE 1.x is used on a system that is running Windows XP or Windows Server 2003.

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.