Windows device database does not seem to scale well.

Our company has developed some USB sensors. Each sensor has a unique serial number that is reported to the host computer during USB enumeration. It is apparent that Windows remembers the serial number of each device that has ever been plugged into the machine, because Windows behaves differently the first time a given device with a specific serial number is plugged in than on subsequent plug ins of that specific device. We can also see the devices in the Windows database by using the SetupDiGetClassDevs() and SetupDiEnumDeviceInfo() functions to walk thru the device list.

Our sensors are HID USB devices and we use the default HID drivers from Microsoft to communicate with them. The first time a specific device is plugged into the system, Windows takes awhile adding the device to its database before it is visible to applications. Because we are using the standard HID device driver, the user is not subjected to the Found New Hardware Wizard, but it still can take quite awhile before the device is available to applications(> 2 minutes).

Usually we can live with a delay the first time a device is plugged in, but it is causing a real problem in our Production department. The Production department has to calibrate each sensor, so a single Windows computer can have several thousand sensors plugged into it over a period of time. Apparently, as the Windows device database has gotten bigger and bigger, the time it takes Windows to add a new sensor to the device database has lengthened, so now Production is slowing down noticeably on calibration.

We tried to prune the device database by walking thru it with SetupDiGetClassDevs() and then calling SetupDiRemoveDevice() for the devices that correspond to our sensors. This seems to help, but I am not convinced that the Production machines are completely back up to speed. Is there a documented way to clean up the device database?

We may have to format the hard drives and reinstall Windows, but surely there must be a better way to deal with this problem.

 

There have been several discussions about this and they can be found in the
archives here or ntdev. Using a Ghost image to restore the machine at the
end of the day will keep the growth from extending beyond that day.
Microsoft's design is for Windows to remember all devices that have ever
been on that machine. Can be a real pain for your needs.

serial number that is reported to the host computer during USB enumeration.
It is apparent that Windows remembers the serial number of each device that
has ever been plugged into the machine, because Windows behaves differently
the first time a given device with a specific serial number is plugged in
than on subsequent plug ins of that specific device. We can also see the
devices in the Windows database by using the SetupDiGetClassDevs() and
SetupDiEnumDeviceInfo() functions to walk thru the device list.

Microsoft to communicate with them. The first time a specific device is
plugged into the system, Windows takes awhile adding the device to its
database before it is visible to applications. Because we are using the
standard HID device driver, the user is not subjected to the Found New
Hardware Wizard, but it still can take quite awhile before the device is
available to applications(> 2 minutes).

but it is causing a real problem in our Production department. The
Production department has to calibrate each sensor, so a single Windows
computer can have several thousand sensors plugged into it over a period of
time. Apparently, as the Windows device database has gotten bigger and
bigger, the time it takes Windows to add a new sensor to the device database
has lengthened, so now Production is slowing down noticeably on calibration.

SetupDiGetClassDevs() and then calling SetupDiRemoveDevice() for the devices
that correspond to our sensors. This seems to help, but I am not convinced
that the Production machines are completely back up to speed. Is there a
documented way to clean up the device database?

there must be a better way to deal with this problem.

 

Are you talking about build-up of instances due to USB "serial numbers"?
Without serial numbers, if you connect them to same USB port, new instances won't be created and detection should not take much
time. There is a registry hack that disables serial number for specific hw id.
--PA

during USB enumeration. It is apparent that Windows remembers the serial number of each device that has ever been plugged into
the machine, because Windows behaves differently the first time a given device with a specific serial number is plugged in than
on subsequent plug ins of that specific device. We can also see the devices in the Windows database by using the
SetupDiGetClassDevs() and SetupDiEnumDeviceInfo() functions to walk thru the device list.

specific device is plugged into the system, Windows takes awhile adding the device to its database before it is visible to
applications. Because we are using the standard HID device driver, the user is not subjected to the Found New Hardware Wizard,
but it still can take quite awhile before the device is available to applications(> 2 minutes).

department. The Production department has to calibrate each sensor, so a single Windows computer can have several thousand
sensors plugged into it over a period of time. Apparently, as the Windows device database has gotten bigger and bigger, the time
it takes Windows to add a new sensor to the device database has lengthened, so now Production is slowing down noticeably on
calibration.

the devices that correspond to our sensors. This seems to help, but I am not convinced that the Production machines are
completely back up to speed. Is there a documented way to clean up the device database?

 

In HKLM\SYSTEM\CurrentControlSet\Control\UsbFlags registry key, add a value:

IgnoreHWSerNumXXXXYYYY=01 (one byte value), where XXXX is hex vendor ID,
and YYYY is hex device ID. Important to have the value as binary, single
byte.

serial number that is reported to the host computer during USB enumeration.
It is apparent that Windows remembers the serial number of each device that
has ever been plugged into the machine, because Windows behaves differently
the first time a given device with a specific serial number is plugged in
than on subsequent plug ins of that specific device. We can also see the
devices in the Windows database by using the SetupDiGetClassDevs() and
SetupDiEnumDeviceInfo() functions to walk thru the device list.

Microsoft to communicate with them. The first time a specific device is
plugged into the system, Windows takes awhile adding the device to its
database before it is visible to applications. Because we are using the
standard HID device driver, the user is not subjected to the Found New
Hardware Wizard, but it still can take quite awhile before the device is
available to applications(> 2 minutes).

but it is causing a real problem in our Production department. The
Production department has to calibrate each sensor, so a single Windows
computer can have several thousand sensors plugged into it over a period of
time. Apparently, as the Windows device database has gotten bigger and
bigger, the time it takes Windows to add a new sensor to the device database
has lengthened, so now Production is slowing down noticeably on calibration.

SetupDiGetClassDevs() and then calling SetupDiRemoveDevice() for the devices
that correspond to our sensors. This seems to help, but I am not convinced
that the Production machines are completely back up to speed. Is there a
documented way to clean up the device database?

there must be a better way to deal with this problem.