Thanks for your fast reply. I thought about it and yes I made other changes to my Windows installation files before Here's exactly what I did: At first I integrated SP2 into my XPCD folder using the /integrate switch. Then I replaced the Luna theme with the Royale theme (including bliss.jpg and logon.scr) and changed all Luna resources in the dosnet.inf, layout.inf and txtsetup.sif to Royale. After this I replaced the logonui.exe, msgina.dll and shell32.dll in my XPCD folder with xpized ones (same file version) since I wanted to integrate the logon, logoff and shutdown screens into my installation. I used modifype and makecab on each file. I tested my installation and everything worked fine until that point. At last I integrated XPize into my XPCD folder and when I tried to install Windows the error occured. I hope this is enough information for you to tell me how to avoid the error. Thanks for your support.