Fer, once "what gets over 90%?"; The amount of used disk space on the system partition or the partition holding the virtual memory pagefile? The physical memory in use?
Versions of Windows these days allow you to tweak the virtual memory pagefile max size, and its usually setup by default to be less than 1GB on most systems (XP seems to try to optimize this). I have one system with 700MB commited, the other with 1/2 that (that one has more physical memory).
So if you had a 30G system partition, were swapping on that partition and had 1 or 2 GB free at all times, that should be sufficient and it is less than the 10% rule. Sure, more is better, but not necessarily needed if you aren't using that partition to install apps and documents within. And, let's say it was a 80GB HDD, then having 8GB free is great, but again, more than overkill if only considering growth for a pagefile.
I guess I am saying that percentages of drive space is less than meaningful for allotting space for the pagefile. The meaningful number is found under "My Computer->Properties->Advanced->Performance..." Find out what your max pagefile size is, double that, and you should be good to go. That's your low water mark, IMHO. A couple of GB total, committed for pagefile growth should be overkill. No, don't set your pagefile that big...just make sure you have a least that amount available free at all times on the swap partition.
TJR
