Advanced system utilities to manage, troubleshoot, and diagnose Windows and Linux systems and applications.
Current versions of Process Explorer that can be downloaded from Microsoft's site are not compatible with Windows XP/Server 2003R2.
If you are comfortable downloading from a non-Microsoft site version 16.05 (indicated to be compatible with XP and higher and Server 2003 and higher can be found at https://web.archive.org/web/20151208231511/https://technet.microsoft.com/en-us/sysinternals/bb896653