I wanted to see what would happen if I overlapped service packs on each other. Used: 1. Innotek Virtualbox 2. XP Home CD. SP0. Unattended only. 3. SP3-5503, SP2, SP1a. 4. nLite 1.4.1 Results: Single Slipstream - SP3 C: 9233 Files, 575 Folders = 1.13GB, 1.00GB on disk. Triple Slipstream - SP3 + SP2 + SP1 C: 9260 Files, 590 Folders = 1.14GB, 1.01GB on disk. Count was done immediately post-install. No restart. Nothing modified. I selected the contents of C: and just got a count from explorer. What could be causing the size difference? Is there any way to compare the contents to find the extra junk? Would it be useful to try HFSLIP too?