How to fix a "Scan failed" error in Canon MP Navigator when scanning with Windows 7.

It was late. I should have gone to sleep by now. I wanted to go to sleep. I was about to shut down my laptop and get ready to go to sleep. But I remembered I had to scan a document then email it. I should have done this weeks ago. It’s late, but I’ll quickly do it anyway. Shouldn’t take long. The laptop is on, the Canon Multifunction MP800 is right there next to it, thanks to a recent reorganisation of furniture so that all the computer equipment is in one place, and I have the document right here.

How long could it possibly take? (Ha! I had to ask!)

Always far longer than I expect, it seems.

I turn on my temperamental MP800 multifunction printer/scanner and wait for it to complain it’s out of ink.

Yes I know you are out of ink, and I don’t care, because I use the cheap laser printer next to you for my printing needs, to avoid the corporate extortion that is inkjet ink prices, so you have been relegated to just occasional scanning duties. Now hold still while I semi-randomly hold down various combinations of buttons on your control panel until I eventually manage to dismiss your annoyingly persistent errors.

I start up the Canon MP Navigator application on the laptop, which has usually done a serviceable job of scanning documents and saving them as PDF files. I place the document on the scanner. I click the “Scan to PDF” button in MP Navigator. MP Navigator seems to sit and ponder this task for a while, and then a “Scan failed” error message appears. Thank you for that oh so helpful and detailed error message you useless piece of corporate bloatware. What do mean “Scan failed?” The scanner is right there next to you, all plugged in and waiting for your command!

And you were working fine last time I tried this.

At least I think you were.

This actually did get me thinking. I suspect I might have been doing most of my scanning in the past with my old Vista laptop, where everything was working fine. However I was sure that at some point reasonably recently I also did some scanning with my this particular laptop in question — a newer Windows 7 machine. In any case, it certainly had all the right software installed. But I suppose it is possible that while I did install all the required software, I have never actually tried scanning from this particular laptop. I have almost certainly printed from this laptop, but perhaps I have never used it for scanning?

In any case, scanning is now broken.

So much for an early night. Because I Will Not Be Able To Sleep Until I Get This Fucking Thing Working.

I go to the Canon website. I check for newer versions of drivers and MP Navigator. Looks like my system has the latest versions of everything.

I delve into the dark depths of the start menu, looking for any other piece of software that might be able to scan. I do actually find something, and manage to successfully scan an image using a different piece of software already installed on my system. This would indicate that the actual scanner is working, so the problem must be with the MP Navigator software. Unfortunately while I can get a scanned image, I can’t export to PDF with this other software, so I still need to work out what the hell is wrong with MP Navigator.

So I google. Eventually, I manage to find a solution.

I get scanning working by adding the following directory to the user PATH environment variable:

C:\Windows\twain_32\MP800

For those not used to delving into the long forgotten labyrinthine depths of the Windows 7 Control Panel to change an environment variable, follow these steps:

• Navigate to Control Panel-->System and Security-->System.
• Select the “Advanced system settings” option that’s attempting to hide unobtrusively in the sidebar, which will bring up the “System Properties” dialog.
• Go to the “Advanced” tab, and click on the “Environment Variables” button at the bottom.
• Pause momentarily to marvel at the simplicity and intuitiveness of Windows.
• Select the PATH environment variable from the list, then click the “Edit…” button.
• Add the above directory to the list of semi-colon separated directories already there.

Scanning should now work.

After doing the above I was able to scan and save documents as PDF using MP Navigator. Better late than never.

As is often the case with these things, the problem was relatively straightforward to solve once I knew what the problem was. But the weird thing is I don’t remember having this problem, or having to manually configure this environment variable, on my old Windows Vista laptop.

The whole thing reminds me of an old Eddie Izzard routine. “Control-P-print” indeed. Or in this case, “Scan, damn you!”