Does this happen only on one system or on all your systems running Trend Micro?
All our sytem.
Do you have Trend Micro's uninstall password set?
Yes.We set the Trend Micro's uninstall password
Have you tried using Trend Micro's uninstaller manually to see if the uninstaller is functioning correctly?
Yes.We can uninstall the Officescan 10.5 from Add/Remove programs.
What are the symptoms, do you get any error messages, can you better describe what is happening?
Using SEPprep.exe and we can install the SEP 12.1 but Officescan 10.5 still stay on system.
Can you send me the SEPprep.log file?