Dave CCleaner:
Can you recall which 5.4x version you were updating from? Was this in response to an in-product notification advising that you were 11/12/13 released out of date?
Possibly 5.44 but I'm not sure. There was a reminder that there was a newer version to download. I usually ignore those because they just tend to add bloat that I don't use.
At what point did Trend Micro pop up during the first failed install attempt? Do you recall what it said when it did pop up?
During the installation the progress bar was perhaps 1/3 to 1/2 across. I think TM's message was t