When using the MDT (Microsoft Deployement Toolkit) to deploy our operating systems and applications, I found a strange problem. I was adding new applications to MDT and testing it in a deployment. After adding the virusscanner software, I noticed several applications where no longer installing and came back with an error :

litetouch unable to set working directory

The applications that had problems, where directly started after the installation of the virusscanner. To solve this problem, I selected to restart the computer after the installation of the virusscanner. You can set this option in MDT on the Details tab of the application. Select “Reboot the computer after installing this application“. 

When testing a new deployment, the computer restarted after the installation of the virusscanner and all the other applicatons installed perfectly.