There is a workaround - I've done this on mine - your mileage may vary and is at your own risk This came from the mobile read forums
You will need to download a partitioning tool (I used the free MiniTool Partition Manager) and you will need access to a none Win10AU PC for back up.
Plug your reader into a PC that has not had the upgrade and backup (copy all folders and files) the reader drive to that PC.
Plug the reader into your windows 10AU PC and use the MiniTool Free Partioning software to format the eReader drive as FAT32 with MBR. Once complete "safely remove hardware" and unplug the reader.
Switch off the reader (complete power down) and then switch on again. It will go through the set up process (Enter language etc)
Once set up, go back to the PC you used to back up and copy back across the folders and files (if any are shown as duplicates with files the reader has just created do not copy back)
That is it. This worked successfully on mine and others on the mobile read forums.
I also reported the issue to Kobo, but they say they are still "gathering information" despite several people having reported this whilst the insider builds were rolled out.
It looks like there is something in the MBR that windows 10AU doesn't recognise, despite the fact that it should already be formatted as FAT32 MBR. All the workaround does is to format the reader partition correctly so that both the reader and Windows can see it.
A factory reset goes back to the old format.
Well. I plugged my Kobo into a different machine. A USB3 port on a Lenovo laptop that is running the first Insider build of W10 (14901:1000) after the Anniversary update (14393.57). I don't know what differences there are as MS just says it is the first of several new builds that will have little or nothing to show.
Anyway, Windows came up and said your Kobo ereader needs repair would you like to scan and repair. I said yea and it scanned for a few seconds and then said 'no problems found' and showed me the file list on the Kobo.
I downloaded Calibre which immediately recognized the Kobo and the books therein. I am now copying my enormous library to the laptop and I imagine it will work fine. It does work fine.
Later I will plug the kobo into this desktop (Anniversary edition) both into USB 2 and USB 3 ( used an aftermarket driver) to see if it works. Later: It doesn't.
Last edited by tplocke; 15 Aug 2016 at 15:54.
I contacted Kobo last Tuesday (Aug 16) and did a live chat with their support. They acknowledge that Kobo's aren't recognised by windows 10 after the update. In the live chat, he said Microsoft was working on the problem and hoped to have a fix in early September. In their follow up email, Kobo said they were working on the problem. So not sure who is working on it, but at least it is officially recognised as a problem
I haven't updated my specs, but I am now on windows 10
After the two W10 updates on the 23rd the Kobo connects and works as it did before. So I guess this is closed.
Cumulative Update for Windows 10 Version 1607 for x64-based Systems (KB3176934)
Update for Windows 10 Version 1607 for x64-based Systems (KB3176936)
Winver now : Version : 1607 (OS Build 14393.82)