Installing USB devices, again, again and again...

[rogerg (Roger)]

OK, so I know I should know the answer to this, being a computer programmer and coming from such a geeky past, but, really, I don't get it.....

Does anyone understand why I would need to install USB devices for each plug they go in to? For example...

I have a 3 port PCMCIA USB2 card that I use in my laptop. If I plug a USB device (any) in to port A for the first time ever, windows will detect it and install software. If I then plug it in port B, windows will think it's new again, detect it, install the same software. If I then plug it in port C, it'll do the same again! AND, then, if I plug a hub in to Port A, if I plug the device in to port A on the hub it'll install it all again, and for port B on the hub, and port C on the hub, and and and....

I don't understand why it would consider every port to be different, why doesn't the one install suit all the USB ports?

WinXP SP2, 2ghz laptop with PCMCIA USB2, built in USB1.

I have worked around this for YEARS, but now I just have to know what's going on



Roger.

[DeanoNZL (Adrian)]

Hi Roger,
There is a registry entry in Windoz that remembers the driver location per USB device.
But, it has to have seen the device at least 1 time on that port to remember it.
When I get a new device, I take time to plug into every USB port. Takes a while, but you only do it once. 3 Laptop & 7 Hub ports later...

"Computers will make our lives easier" Yeah Right.

[rogerg (Roger)]

Thanks Adrian

It sure is a pain... I'm surprised it doesn't look through existing installations to find a match first.

[bird (Anthony Wesley)]

Only under Wndows does this happen...

Bird

[33South (Chris)]

My understanding is that part of the spec for USB devices is that each device should have a unique serial number, this is how Windows recognizes the device.
If the device has a serial number then Windows remembers the device whichever USB port is used.

However the serial number is optional, so the USB device manufacturers dont bother to provide one.
Sometimes they compromise and there is common one across all their devices, this is ok until you try to plug in a second device - usually a spontaneous reboot.