You mention that when Trend updates, your virus protection is turned off.. As long as you only have Trend installed as your virus protection, then I don't think there's a problem.. During many such updates Trend Micro's scanning program will shut down temporarily to install its updates. It can't perform the update unless it shuts down briefly. When the update is completed, then Trend restarts and enables itself again.
Hope this helps.
When I update my Trend Micro security software, I get an alert from windows security that informs me that my virus protection has been disabled. If monitored I can see that it is turned off. After the Trend update the virus protection is turned back on. This seems to be a possible compromise with the software. I did not have this problem with my previous security software.