It shouldn't be anything to do with Windows not being updated...

Try doing something like this,

Keep a log over two to 3 days of the file size for,
-C:\Windows
-C:\Program Files\
-C:\Documents and Settings\Username (or C:\Windows\Profiles I think it is in Win9x)
-Any other folder in C:\ that you think you should look at.
-The Harddrive itself

And see what changes. Maybe you should consider reinstalling Windows, give it a fresh start.


Just thinking, are you running any kind of Firewall? ZoneAlarm used to make huge logs for me, getting up into the 100's of mb over a few months.