I just set up 6 identical Dell OptiplexXE machines with Office Home and Business 2010 pre-loaded. Reader 10.1.1 will run in protected mode if it is installed before I go through the Office 2010 activation/installation procedure. On the 2 machines where Office was set up before installing Adobe reader, protected mode will not work. If protected mode is not enabled, I cannot go into preferences - general and turn the protected mode log to try to debug this problem. For now I an running those two machines with protected mode off. Has anyone else seen this?