Have a win xp pro machine that says low disk space. Ran tree size and it shows that there is plenty of space. Is this a virus? This happened on Friday on one of my machines. Now the same thing just happened on another one. Low disk space. This is also win xp pro. Seems like a malware or virus. Any ideas on what to do? The first pc I was able to copy everything off and when I had to reboot it would just cycle throught rebooting and now the pc is useless unless I reinstall OS.