PAE (Physical Address Extension) enables your server to use more than 4 GB of RAM.

If you run Winver.exe and it reports more than 4 GB of memory, then the PAE specification is being used.

The /PAE switch in the C:\boot.ini file enables PAE, but some servers with hot plug memory enable PAE when the /PAE switch is NOT set in the C:\boot.ini file, unless the /NOPAE switch is set. The /NOPAE switch in the C:\boot.ini file disables PAE.

To verify that the /PAE switch is enabled on your server:

<b>NOTE:</b> The follow scriplet uses <a href="/article/jsifaq/jsi-tip-9766-how-can-i-retrieve-the-amount-of-memory-in-a-computer-from-the-registry-.aspx"><b>GetMEM.bat</b></a> and <a href="/article/jsifaq/jsi-tip-7431-a-better-way-to-determine-the-length-of-a-string-.aspx"><b>VarLen.bat</b></a>.

set PAE=0x0
:: NOTE: PAE is enabled when PAE=0x1
call :getPAE>nul 2>&1
if "%PAE%" NEQ "0x0" (
 @echo PAE is enabled on %ComputerName%. Memory is %MB% MB.
) ELSE (
 @echo PAE is NOT enabled on %ComputerName%. Memory is %MB% MB.
)
. . .
. . .




:getPAE
call GetMem MB
set key="HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management"
for /f "Tokens=2*" %%a in ('reg query %key% /V PhysicalAddressExtension^|find "REG_DWORD"') do (
 set PAE=%%b
)
goto :EOF