WinXPproSP3 CD In order to install WinXPproSP3 off-line I created a CD, based on this link : http://www.microsoft.com/downloads/...ce-b5fb-4488-8c50-fe22559d164e&displaylang=en After burning that ISO-file, the CD was OK and working properly. Installation of WinXPproSP3 I installed SP3 in my online snapshot and at the end of the installation, it stucked and didn't continue anymore. The screen mentioned these two lines : Finishing installation Running processes after install I ended the installation in Task Manager and used my boot-to-restore to uninstall the leftovers of an unsuccessfull installation of SP3. Problem I installed SP3 in other images without a problem and that means there was nothing wrong with the CD. All the tested images had one thing common : no security softwares installed. My online image however has 3 security softwares : 1. Sygate Personal Firewall Pro 2. Anti-Executable 3. DefenseWall An infection was in theory impossible because of my personal procedures for using ISR in combination with IB. Anti-Executable was OFF during the installation and I even uninstalled it completely. The problem was still there, so it wasn't Anti-Executable I uninstalled Sygate Personal Firewall Pro completely and the problem was still there, so it wasn't SPFP either I disabled DefenseWall and the problem was still there. I UNinstalled DefenseWall completely and the problem was gone and SP3 was finally properly installed. I had the previous version 2.40, so I installed v2.43, exactly the same problem. Conclusion If DefenseWall v2.43 is installed, enabled or disabled, you can NOT install SP3 and it causes a mess in your system. If DefenseWall v2.43 is NOT installed or UNinstalled, you can install SP3. I also tested Windows Update (online) and the same problem. DefenseWall-users can test this easily, based on this post, but backup your system FIRST, otherwise your actual system will be a mess.