Error when opening Zoombrowser 6.5.1 and 6.6.0

Hi,
I have a pb opening Zoombrowser 6.5.1. The issue is a critical error ID event 1000 from event viewer. I uninstalled, resterted and reinstalled from disk: the version 5.7 runs the upgrade doesn't. Also the 6.6.0 doesn't run.
I have win xp SP3.
Any idea?

Hmm -- I'm away from my XP workstation so can't check my version there -- in fact I don't think ZoomBrowser is actually installed on that machine, I don't recall, and my laptop here is a Win7 64 and is running ZB 6.4.1 with no problems. I'll assume that you didn't accidentally install the update accidentally switched to the wrong OS. So, no clue -- you could try searching for the meaning of that error code and see if there's a clue but more likely "event 1000" is a "generic" type of message.

Maybe find an earlier version to "downgrade" to?

For me, ZoomBrowser isn't something that there would be a compelling reason to make me keep upgrading. The only reason is if I were to use it to download shoots from a camera that is too new to communicate with ZoomBrowser, and I myself use a card reader, and anyway all my cameras are fully supported by all the Canon apps.