When windows xp is copying files from the cdrom, it stops at two points, telling me that Nikedrv.sys and mdwmdmsp.dll cannot be copied. I've had this message before, but then it worked nevertheless. Now I've tried to make an unattended install with sp1a and the rollup package slipstreamed. The cd also contains norton antivirus 2004 and the autopatcher 4.5, but I don't think the error lies with the two latter components. And now after the copying, when the machine has rebooted, it enters setup, and bang! the following message pops up: Setup Failed To Install The Product Catalogs. Detailed Info Button: The Signature for Windows XP is invalid. Error Code 800b0100 Does anyone have a clue about what's going on?