xp memory issues

Factual Questions
1

I have about 750M RAM that occasionally gets completely full (Firefox and Outlook I am looking at you). But there are times that I have only say outlook open after closing everything else, and only 10M free, but cant see anything on the task list that is taking up the memory (the totals only seem to add up to 300 M or so in task manager).

Is it possible that XP has lost track of the memory or that task manager is not reporting all the memory being used? Is there another programme that is able to track all the processes and memory leaks/usages to find the cuplrits?

2

Which version of Firefox? Prior to version 3x, Firefox was a notorious memory leaker.
Try the technique listed here. It might help you find what’s leaking.

3

I suspect the culprit is outlook 2003 which seems to grab VM and never let it go. Also my missing memory may have been due to monitoring RAM, not VM in task manager. I note your suggestion of perfmon which looks interesting - though not quite sure how to use its data and the link doesnt really explain but I will google around