I have a Fujitsu fi-6130 automatic document feeder scanner that is truly impressive, it will feed and scan double sided, 300 dpi, at a rate of 30 sheets per minute, or in other words, 60 images per minute in black and white, somewhat slower in color.

SWMBO has a nice Epson 4490 flatbed scanner that is slow (about 20 seconds to scan a single page) but is designed to scan color photographs at high quality.

I wouldn't want to try and create an eBook from a paper and ink book with her scanner. I wouldn't want to try and scan my Permanent Resident visa card with my scanner (the source material has to bend about 75 degrees to go through the scanner). Each scanner has its uses. Both of them connect via USB.

Since she never uses her scanner, and I absolutely hate doing battle with her iMac whenever I need a flatbed scanner, I had the bright idea to connect both her scanner and my scanner to my computer so I could just choose whichever scanner was better suited to the job at hand.

So, I downloaded and installed the Epson drivers and UI software for my computer, and it worked like a charm. The Epson software is very versatile and is actually better than what I have for my Fujitsu.

Then this morning I wanted to use my ADF scanner, only to find that apparently the Epson drivers over-wrote the Fujitsu drivers, and the Fujitsu would no longer work.

These are both TWAIN drivers, and are unique to each separate scanner. I reinstalled the Fujitsu drivers (latest update) and now the Fujitsu works, but of course the Epson will not.

Is it possible to have these two scanners co-exist on the same computer? If so, how would I do it?

tanstaafl.

They really should just co-exist unless underneath they are identical. Even then they should present as different USB devices. Do they both show up in Device Manager?

This really should be quite simple. You would then just select the appropriate scanner in your scanning application.

My single flatbed scanner even shows up as two separate scanners one with "WIA-WIA" in front of it. I've never bothered to figure out why as both seem to work just fine.

Excellent question. Hard to find a straight answer just by googling.

Question, if you go to:
- Control Panel
- Hardware and Sound
- View Devices And Printers

Are both scanners listed there? Or only the most-recently-installed one?

If they are both listed there, then maybe it's just a question of right-clicking on the desired one and selecting "Set as default" and then using that one.

If they're not both listed there, then you might be right: Maybe you can only have one TWAIN USB scanner at a time.

Seems like something they would have fixed in Windows 10 by now, but maybe not.

Yes, both scanners are listed, but there is no "Set as default" option that I can find.

After a lot of experimenting with installing/removing drivers and software, I have come to some conclusions. Probably wrong conclusions, but I don't claim to be smart.

I don't think it is a driver conflict problem. The scanners show themselves to be on separate USB ports, and both scanners pass the Windows diagnostic test. See the screenshot.

Operationally, the problem seems to be that if the EpsonScan UI software is installed, it takes over any and all scanning operations, that is, it won't let me use the Fujitsu scanner even though I start out using the Fujitsu's software. As soon as I tell the Fujitsu software to scan, it brings up the EpsonScan software and the job goes to the Epson.

If I then go to Devices and Printers and Uninstall the EpsonScan software, the Fujitsu works properly.

I went so far as to rename the escndv.exe program, and the damn thing still ran. The only way I can find to stop it is to do a full Epson uninstall.

Knowing that, I suppose I could put shortcuts to the Epson Uninstall program and the Epson Install program in my Scanners directory and on the rare times I need the Epson flatbed scanner just install it and uninstall it when I'm done, but that is far from an elegant solution. Pretty ugly, actually, it would almost be easier to just leave it on the iMac. [shudder!]

I dunno what to do from here.

tanstaafl.

What happens if you try to scan from a different piece of software other than the EpsonScanUI software? Like, if you have a photo editing app and you try to scan from that app?

I seem to recall that programs which leveraged TWAIN would give me the choice to choose which scanner to use. I could be remembering that wrong though.

I almost have it solved. Of course, the "almost" may be insurmountable.

If I rename the directory containing the Twain driver for the Epson scanner, then everything works (except for the Epson scanner, of course.

So, I wrote a batch file that will rename the escndv directory to XXescndv, and another one to name it back. The batch files work like a charm... as long as I am in the C:\Windows\Twain_32 directory with an administrator command prompt.

Is there a way to change the permissions on the Windows\Twain_32 directory so that I, a mere user with non-elevated administrator privileges, can write and modify files in that directory without doing battle with the security nanny? Or is there a way that I can have what would be called Super-User privileges in a *nix box?

tanstaafl.

Yes.

Make sure that your batch file starts with a command which does a CD to the correct directory, because the steps below are going to mess up the starting "current" directory of the batch file.

Create a Windows Desktop Shortcut which points to your batch file.

In the PROPERTIES of that shortcut, press the ADVANCED button.

Tick the "Run As Administrator" tickybox and save the properties.

Now if you run that batch file by clicking on that shortcut, it will run with administrator privileges (and probably pester you about such, each time you run it).

There are ways to work around the pester box if you want that too.

Clarification about the CD thing....

Most batch files, if you run them, their "current working directory" will be the directory in which the batch file resides. It is also possible to change the current working directory of any batch file or program by making a shortcut and then changing the working directory in the properties of the shortcut.

Recently, Windows has had this thing called "UAC" which prevents programs from running as an administrator unless you tell it otherwise. So they added that advanced shortcut property setting I talked about, to allow you to create a shortcut that defaults to running as administrator. So far so good.

But one of my pet peeves is that they fucked it up. Now, when you create a shortcut that runs as administrator, it fucks up the working directory. No matter what you set for the working directory in the shortcut properties, the working directory always gets changed to the Windows System folder if you've ticked the "administrator" tickybox. It's been this way ever since Windows Vista I think.

So now everyone's batch files has to CD at the beginning of the batch file when they didn't need to before. I have no idea how something so egregious, something that immediately breaks everybody's batch files, didn't get repaired right away, and even persisted through four major OS releases. Sigh.

By the way, the secret trick that you can put at the top of all your batch files, which will always set the working directory to be the location of the batch file itself, is this:

I had done all that, and it still didn't work.

So after reading your post, I went back and double-checked everything, and somewhere with all the fiddling I had done, the tickybox had gotten unchecked.

Once I checked the tickybox again, it all worked perfectly.

Thank you!

tanstaafl.

I'm trying to remember a good explanation of the situation, and why it's likely to never be "fixed" in the way you want. After close to 10 years of UAC, it seems clear Microsoft doesn't intend to modernize DOS concepts in the security model they adopted to protect the OS. Users of Microsoft products got used to them adding amazing level of complexity to the product to stay backwards compatible with concepts from the single user PC era of the 80s. That complexity blew up in Microsoft's face during initial NT development, again during Longhorn development, and lastly during Windows 9 development. It's becoming clear their idea of legacy support now is to containerize and virtualize it.

The sooner companies adopt the practices laid out in Windows 10 for legacy apps, the sooner the Windows platform can become even more competitive in the landscape today. Overall as someone who dislikes monopolies, the new Microsoft continues to impress me for providing some solid competition again.