Solved UMBus Root Bus Enumerator - Unknown Device

[Natikabu]

Hi there,

I tried to install a wireless Logitech keyboard/mouse combination. The keyboard works fine, the mouse doesn't. The device manager shows the "UMBus Root Bus Enumerator" as unknown device. I researched in some forums and found this: "sc config umbus start= demand". But it doesn't work.

In this forum I found an older threat with this post:
Go to Device Manager > Action > Add legacy hardware > Next > Install the hardware that I manually select from a list > Next > click on "System Devices" > Next > then under "Manufacturer" click on "Microsoft" then under "Model" click on "UMBus Root Bus Enumerator" > Next > Next

But when I want to install legacy hardware, the software asks for a storage device with the drivers. The installation DVD doesn't work. What to do?

Any help is appreciated.
Natikabu

 

[ComputerGeek]

Check if these 3 files exist

1. C:\Windows\inf\umbus.inf
2. C:\Windows\inf\umbus.pnf
3. C:\Windows\System32\drivers\umbus.sys

 

[Natikabu]

Yes, these files exist in the correct folders.

 

[ComputerGeek]

Look under System Devices. Is UMBus Enumerator listed? Missing? There with an error (yellow icon)

Reboot your machine. Navigate to folder C:\Windows\inf. You should find a file named either setupapi.dev or setupap.dev.log. In either case, zip it and upload to next post

 

[Natikabu]

Yes, both devices are listed. Attached you find both files setup files.

 

[ComputerGeek]

My guess is something corrupted registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\DevicePath

DevicePath is a list of directories. When you install a driver, Windows inspects each directory in DevicePath looking for a suitable driver. DevicePath should ALWAYS include %systemroot%\inf. The log files you provided indicate it's missing from yours. (and that's the directory where umbus driver installation file resides)

Open the registry, look at the key above and show me a screen shot or copy/paste the value so I can see it. Check the key on your other machine too, the one that's working. Show me that one too

It's likely a 3rd party installer corrupted this registry key. Let's compare DevicePath as defined on both machines.

/* EDIT */
Oooops. Had you confused with someone else who had 2 machines. But all I said remains true for you. Show me DevicePath on your computer

 

[Natikabu]

This is the content of DevicePath:
%SystemRoot%\inf;C:\Program Files\Samsung\USB Drivers\01_Simmental;C:\Program Files\Samsung\USB Drivers\02_Siberian;C:\Program Files\Samsung\USB Drivers\03_Swallowtail;C:\Program Files\Samsung\USB Drivers\04_semseyite;C:\Program Files\Samsung\USB Drivers\05_Sloan;C:\Program Files\Samsung\USB Drivers\06_Spencer;C:\Program Files\Samsung\USB Drivers\07_Schorl;C:\Program Files\Samsung\USB Drivers\08_EMPChipset;C:\Program Files\Samsung\USB Drivers\09_Hsp;C:\Program Files\Samsung\USB Drivers\11_HSP_Plus_Default;C:\Program Files\Samsung\USB Drivers\16_Shrewsbury;C:\Program Files\Samsung\USB Drivers\17_EMP_Chipset2;C:\Program Files\Samsung\USB Drivers\18_Zinia_Serial_Driver;C:\Program Files\Samsung\USB Drivers\19_VIA_driver;C:\Program Files\Samsung\USB Drivers\20_NXP_Driver;C:\Program Files\Samsung\USB Drivers\21_Searsburg;C:\Program Files\Samsung\USB Drivers\22_WiBro_WiMAX;C:\Program Files\Samsung\USB Drivers\24_flashusbdriver;C:\Program Files\Samsung\USB Drivers\25_escape

I deleted everything except the "%SystemRoot%\inf" and rebooted the system, but nothing changed. I remember, that the problem began after some software installation, but I don't remember what it was.

 

[Natikabu]

Now the problem ist solved. I tried again the Update Driver option in the Device Manager and manually set the path to Windows/inf. The driver was updated and everything works fine. All new USB devices are found now.

Thanks a lot for your support. It helped me to understand the structures of Windows a bit deeper.

 

[ComputerGeek]

Hi Natikabu

You're most welcome. Glad i was able to help. (And thanks for the rep!)

I'm glad you got it to work but one last thing puzzles me: Your data indicates %systemroot%\inf is, in fact, in DevicePath

So, please verify this: Open File Explorer, type %systemroot% as the file path, hit Enter.

• If Explorer takes you to folder C:\Windows, %systemroot% is OK and i guess this is just another Windows mystery!
• But if you're NOT taken to C:\Windows, then the value of systemroot is corrupt and need be fixed

 

[Natikabu]

Good morning ComputerGeek,

%systemroot% takes me to C:\Windows as it should. It seems we're indeed tapping around in the mysterious realms of Microsoft.

Thanks again and all the best
Natikabu

 

[montg011]

[FONT=&quot]Viewing the posts of August 17-21, I believe I may have the same/similar problem. This involves a Dell Inspiron, Win 7 Home/32 bit setup. I recently installed and ran a trial IOBit registry cleaner/updater/etc. Now the HP OfficeJet 6700 will not function – completely. Running the Devices and Printers troubleshooting function (the “computer” icon – not the printer was marked) I got the response: Programmable Root Enumerator – Failed (that listed twice) and OfficeJet 6700 – no driver found.[/FONT]
[FONT=&quot]As I suspect a registry change/error has occurred, I did try to follow your lookups and instructions within the posts:[/FONT]
[FONT=&quot]1. [/FONT][FONT=&quot]Check If These 3 Files Exist[/FONT][FONT=&quot] [/FONT][FONT=&quot](C:\Windows\inf\umbus.inf; C:\Windows\inf\umbus.pnf; C:\Windows\System32\drivers\umbus.sys)[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot] YES – ALL THESE DO EXIST[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]2. Looking at System Devices, under Other Devices, OfficeJet 6700 is listed three times and all marked with the yellow warning triangle. Under Programming Support, Programmable Root Enumerator is listed three times. The top entry is not marked and indicates it is working properly. The next two entries are marked with a yellow warning triangle and This device is not working properly because Windows cannot load the drivers required for this device. (Code 31). All other files within System Devices are working properly.[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]3.[/FONT] C:\Windows\inf. You should find a file named either [FONT=&quot]setupapi.dev[/FONT] or [FONT=&quot]setupap.dev.log[/FONT].

Two files titled setupavi.setup log are listed at that location. One is dated 10/20/2015 and highlighted in blue. The other has today’s date (when I tried to print/fix). I have zipped these tow text files and they are included.

4. I did follow your instruction and looked at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\DevicePath

What appeared was: DevicePath (type)REG_EXPAND_SZ (data)%SystemRoot%\inf


At that point I’m lost. I can see in the logs the “failure” but have no idea why or how to correct things.

I do appreciate any help--
[FONT=&quot] [/FONT]

 

[ComputerGeek]

Hi montg011

fyi... It's best to start a new thread for your problem as it draws attention to it as a new problem. Others may also be able to help. Your new thread can reference/link back to your original post above.

That said, I'm travelling for another week or so but will try and have a look as i can. Meantime, see if you can do a System Restore to a date prior to the problem.

p.s. Registry cleaners are not worth trouble they can cause. (Or use them only if you know how to restore a system the cleaner may have broke!)