I've been researching this after seeing this on a few computers lately.

Here's what I'm referring to:

A disk check has been scheduled.

Windows will now check the disk.

Cleaning up minor inconsistencies on the drive.

Cleaning up 985 unused index entries from index $SII of file 0x9.

Cleaning up 985 unused index entries from index $SDH of file 0x9.

Cleaning up 985 unused security descriptors.

Now here's what gets me. It's happened on both my server computer and my primary. It's also happening to other's computers as well. So I've been trying to get to the bottom of this. One MSKB shed some light.

http://support.microsoft.com/kb/831374/

I've been seeing this for a while, hadn't gotten around to researching the problem. Got all the XP updates already, so the solution given on that page is no help. Maybe SP3 will fix it...

What defrag software do you have installed? Also, what firewall (if any) do you have installed?

using built in defrag and contig from time to time.

using comodo firewall

A disk check has been scheduled.

Windows will now check the disk.

Cleaning up minor inconsistencies on the drive.

Cleaning up 262 unused index entries from index $SII of file 0x9.

Cleaning up 262 unused index entries from index $SDH of file 0x9.

Cleaning up 262 unused security descriptors.

CHKDSK discovered free space marked as allocated in the master file table (MFT) bitmap.

Windows has made corrections to the file system.

Using the Windows firewall and defragmenter, plus PageDefrag (which doesn't actually install). Just recently installed AusLogics Registry Defrag, but this started previous to installing that.