If you are troubleshooting a hardware issue, or a specific PAE (Physical Address Extension) or AWE (Address Windowing Extensions) issue, you may want to temporarily disable PAE mode. In Windows Server 2003 SP1 and Windows XP SP2, the DEP (Data Execution Prevention) processor features require that the processor run in PAE mode.

NOTE: See tip 8775 » A detailed description of the Data Execution Prevention (DEP) feature in Windows XP Service Pack 2, Windows XP Tablet PC Edition 2005, and Windows Server 2003 SP1.

The 32-bit versions of windows use the following hardware technologies to implement DEP:

• The no-execute page-protection (NX) processor feature as defined by Advanced Micro Devices.

• The Execute Disable Bit (XD) feature as defined by Intel.

To support DEP, Windows automatically loads the PAE kernel. You are not required to add the /PAE switch to C:\Boot.ini.

To disable PAE mode:

1. Open a CMD.EXE window.

2. Type attr -r -s -h c:\boot.ini and press Enter.

3. Type notepad c:\boot.ini and press Enter.

4. Change the appropriate \WINDOW= entry to one of the following, based upon your operating system:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows Server 2003" /fastdetect /execute /NOPAE

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP" /fastdetect /noexecute=alwaysoff /NOPAE

5. Save the file.

6. Type attr +r +s +h c:\boot.ini and press Enter.

7. Shutdown and restart your computer.

NOTE: If the above, or future, 3rd parties change their technology, this tip may no longer function to disable PAE mode.