Did you try it as the virutal memory paging drive?
My Computer | Advanced | Performance Options | Virtual Memory.
I know for sure that NT 4.0 has an event log for low disk space because back
then I had few NT machines with low space disk on the page drive and I use
to see many Low Space event entry warnings. I'll be surprise if MS remove
this for 2000, XP or newer. But for non-paging drives, I wouldn't expect it
and as Pavel said, you have to roll your own on this.
In fact, I googled the words: Low disk space event log
and found this:
Tip #225: Low Disk Space Warning
showing you the registry option for changing the default 90% threshold and
according to the tip, it applies to all volumes, which if true, would be a
surprise to me.
In the same search result, I found this interesting too:
"How To Add Error Logging for Low Disk Space in System Monitor in Windows
and there is a bunch of other useful links on the subject.