W7 has a Resource Monitor in the Performance page of TM. I can't remember if XP did or not.
How does this extended utility compare to Process Explorer?
I have the latter, but what I really mean is in its usefulness to the experts.
I've never used Process Explorer to troubleshoot a runaway task situation, Task Manager has always been adequate (and i've fixed more than my fair share of customer virus/malware idiocy).