JSI Tip 8744. The System Properties dialog box and the System Information tool report an incorrect amount of RAM in your Windows XP SP2 computer?

The subject behavior will occur if your computer has 4 gigabytes or more of RAM and you have the /PAE switch set in C:\Boot.ini.

Without the /PAE switch, a system with 4GB of RAM will show ~3.12GB in System Properties and MSInfo32.exe shows ~2,710MB of RAM, with and without SP2.

With the /PAE switch, before you applied SP2, these values were ~3.87GB and ~3,540MB.

After SP2, with the /PAE switch, these values are ~3.12GB and ~2,770MB.

This behavior occurs because of design changes to PAE mode that improves driver compatibility.

NOTE: See Changes to Functionality in Microsoft Windows XP Service Pack 2.