Cutting to the chase, Irfanview's TWAIN driver selection keeps defaulting back to the original CR-120 driver, but only occasionally and seemingly at random. This happens only to a few specific users, which makes me believe that this must be something to do with the Roaming profiles.
This is probably a very niche problem, but the association that I work for uses Canon CR-120 and CR-150 Check scanners for scanning our daily work documents through the batch mode on Irfanview. Recently, one of our CR-120s malfunctioned and we decided to replace it with a CR-150. They have separate drivers, which I had to add in order for it to work with Irfanview and selected it as the TWAIN source (File > Select Scan/TWAIN source). That worked for a while, but soon (the next day, I believe) I got a call saying that the scanner wasn't working anymore. I found out that some users on the same workstation could use the scanner, but others could not.
I checked Irfanview's TWAIN driver selection and saw that it had reselected the CR-120 driver. I reselected the CR-150 driver, thinking it was a fluke, but then it happened again a few days later, and I dug around a little trying to make some permanent changes (I don't remember what exactly I did, but it hardly matters since it didn't work). Finally, right in the middle of the next week, it happened again so I removed all references I could find of the old drivers from the user's roaming profiles, and I have yet to hear of an issue, but scouring the internet has left me with no answers to what caused this in the first place.
How do I prevent this? Is there some configuration file somewhere that controls Irfanview's default TWAIN settings? Is there at least some list of paths that Irfanview uses that I could work it out for myself? I've tried searching the system files myself and noticed that the Irfanview config file and a folder labelled "ISIS Drivers" both exist in each user's roaming profile, which is also the location where I had to install the config files for the Canon scanners. I have also checked the System32, Syswow64, and registry keys for any mention of TWAIN or ISIS but found nothing usable.
