I hope this is not an inappropriate forum for this question.
Some time ago I connected a SCSI scanner to a Windows XP machine. As I had no device driver for it, it appeared 8 times in Device Manager under "Imaging Devices" (as "Flatbed-Scanner SCSI Scanner Device") and invited installation eight times during every startup of the machine. Apart from that inconvenience the scanner worked, at least most of the time.
Today I decided to do something about the inconvenience and tried installing drivers for the eight instances of it, leaving Device Manager to find the drivers. It found and decided to use Microsoft's scsiscan.sys. This got rid of the inconvenience at startup — for a while. Several restarts passed painlessly.
Then on one particular restart the invitations to reinstall the eight scanners returned, and have remained. Investigation shows that the scanners have disappeared from "Imaging Devices" in Device Manager, and in fact "Imaging Devices" has disappeared. The eight instances of "Flatbed-Scanner SCSI Scanner Device" are now to be found under "Other Devices". The installed drivers (scsiscan.sys) have been removed from them, and Device Manager will not not allow this driver to be reattached to them either automatically or manually.
The scanner still works, but the inconvenience at startup is back. What could have induced Windows to change from regarding the scanner as an "Imaging Device" to regarding it as an "Other Device", and to refuse to install scsiscan.sys for it? Absolutely no change was made to hardware or software during this time.
What could have induced Windows to change from regarding the scanner as an "Imaging Device" to regarding it as an "Other Device", and to refuse to install scsiscan.sys for it? Absolutely no change was made to hardware or software during this time.
Well, I DID make a change and it caused the problem! The change was that I uninstalled the VueScan program (running it was crashing my machine with this unsupported scanner attached). Uninstalling VueScan removed a file called "scanners.inf" which VueScan had placed in a subfolder of windows\system32 and which does whatever has to be done to make my scanner an "Imaging Device" in Device Manager. With this file back, the problem is solved for the present.