I have heard of this sort of thing before but cannot recall it ever happening to me. I plugged in my Komplete 61 yesterday after having it unplugged for a few days. When I turned it on I got the message that Windows did not recognize the last usb device connected. Tried a few times with same result, then looked in device manager and found the driver was missing. Downloaded the appropriate driver, reinstalled and it worked. It worked until I had to umplug the USB to fixed a cable tangle. When I plugged back in, it didnt work. Tried reinstalling driver and still no love.Then realized that I had plugged in (both times) yesterday to a usb port that is an expansion off my intel bluetooth and wireless card. I disconnected and plugged into a port directly off motherboard and everything worked perfectly. Lesson learned I guess, but curious as to why the expensiin port is so sketchy!
 
Also, there is no reason why the driver was ever 'missing'. Would a bad connection at usb make windows think the driver was missing??
 
Brian

AFAIK device drivers are installed per USB port. Plugging into different port will require another driver installation which often simply happens in the background but is known to cause issues with some devices where e.g. the driver gets a different name and makes Sonar projects complain. This is e.g. the case with Behringer X32 MIDI driver...

USB hubs, especially ones that are not "self powered" (have their own power supply) are iffy at best.  Depending on what is plugged in there may not be enough power for all the devices.  Best to only use "powered" USB hubs, and some devices should not be on an external hub. 
 
Another issue with SOME devices, if the "Safely Remove Hardware" function (icon in Notification area) is not used to "remove" device before unplugging or powering down, the next time you use it, it will not connect as the Windows status will be corrupted.  When this happens, you have to plug in the device, go to the Device Manager and uninstall the device (mostly you will see an unknown device listed in the USB section), then disconnect the device, restart Windows and then after Windows has started you can connect it and Windows will install the device.

filtersweep
I have heard of this sort of thing before but cannot recall it ever happening to me. I plugged in my Komplete 61 yesterday after having it unplugged for a few days. When I turned it on I got the message that Windows did not recognize the last usb device connected. Tried a few times with same result, then looked in device manager and found the driver was missing. Downloaded the appropriate driver, reinstalled and it worked. It worked until I had to umplug the USB to fixed a cable tangle. When I plugged back in, it didnt work. Tried reinstalling driver and still no love.Then realized that I had plugged in (both times) yesterday to a usb port that is an expansion off my intel bluetooth and wireless card. I disconnected and plugged into a port directly off motherboard and everything worked perfectly. Lesson learned I guess, but curious as to why the expensiin port is so sketchy!
 
Also, there is no reason why the driver was ever 'missing'. Would a bad connection at usb make windows think the driver was missing??

There are several factors: 

• What other device (if any) is sharing the USB Root Hub
• Is that particular USB port sharing an IRQ
• If it's USB-3 and not an Intel controller, there can be compatibility issues (common with Audio/MIDI interfaces)

 

Jim Roseberry

• Is that particular USB port sharing an IRQ

how would you check that?

Device Manager>View>Resources By Type>Interrupt Request

I was wrong in initial post. It is next to the bt/wireless card but is actually just a 2 port usb plugged into to mobo. Should have known that - i just built ghis comouter last summer. Anyway, i think Fireberd may have nailed it. I didnt remove the s61 "safely" and prob did corrupt the driver.

Drivers are the necessary weakest link in the system. I find I'm updating or reinstalling them more as time goes by.

I've found in the past that this can happen due to a bad driver getting cached in c:\windows\inf\oem*.inf.  If you plug in certain devices without a driver, Windows seems to get confused about what it is and creates an oem*.inf file that essentially locks that specific port and device to a driver that doesn't work.  You see lots of warnings in manuals about not plugging in devices until after you've installed the driver and I suspect this is why.  For whatever reason, the good driver install works the first time but then doesn't hang around for the next port you plug it in.  I don't know if this is a Windows oddity, a USB standard issue, or just the driver developer didn't develop the driver and/or installer properly (drivers are complicated things to get right).  You can usually track down the specific oem*.inf file by matching up the file's created date/time to when you plugged into the wrong port.  If you wanted to move to that port, you could delete the .inf, rerun the installer, and then plug into the new port.  
 
I also agree with what others have said that different USB hubs can have weird behaviors.  This seems to usually be power/current related.  Some hubs seem to be designed for simple needs like a mouse or flash drive and not something as sophisticated as a Komplete.  Even two internal USB ports can be on different internal hubs -- for example, front ports versus back ports might be different internal hubs.  
 
This software is nice if you are curious about seeing what the USB device tree on your system looks like:
http://www.uwe-sieber.de/usbtreeview_e.html
 

Don't forget the internal physical connections. Often, the port is connected to the motherboard via a small ribbon cable. It only has to be slightly ajar to cause USB connections to be intermittent or to not be recognized by the system.