How do i change my USB device's blocked Class ID?

July 9, 2009 8:22 AM

How do i change my USB device's antivirus blocked Class ID?

The facist antivirus on my windows XP machine is blocking various USB devices on the basis of Class ID.

Mass Storage devices with 08h ID are all blocked

HID device with 03h IDs are allowed

Is there anyway I can reclass a USB device itself
or
force windows to read 08h devices as 03h?

any ideas to get around it

posted by complience to Computers & Internet (9 answers total)

Response by poster: another brilliant answer from the hive mind - i love ask meta
posted by complience at 8:42 AM on July 9, 2009

Another issue; If you change the class ID, Windows won't know what drivers to use and the device won't work.
posted by smackfu at 9:02 AM on July 9, 2009

Even if you could change the base class of the storage device to 03h, all that will get you is a drive that Windows thinks is a human interface device, like a keyboard or mouse. It will try to use a HID class driver to talk to it, which won't work, since it's a storage device.
posted by zamboni at 9:03 AM on July 9, 2009

Response by poster: That would be a good start, how would I go about doing that?

As it would at least allow me to charge my Iphone using the USB adapter

at the moment it just gets blocked and no charge is received.
posted by complience at 9:31 AM on July 9, 2009

Maybe I'm just naturally suspicious, but is this a corporate machine with a policy to block those devices, so you don't have access to actually change the antivirus settings?
posted by JaredSeth at 9:42 AM on July 9, 2009

Complience, I'd be shocked if most USB devices didn't contain their base class IDs in hardware, meaning that you can't change them -- for example, I doubt there's anything you can do about the base class of a USB thumbdrive, it's dictated by a chip on the drive itself. Perhaps some more complex devices like iPhones might have them in their firmwares, but even then, you'd be talking about installing a custom firmware on your iPhone... to be able to charge it? That'd be way too complicated and unmaintainable a solution, especially given how easy it is to charge it via a wall plug.
posted by delfuego at 12:44 PM on July 9, 2009 [1 favorite]

You don't mention the type of antivirus used. There are sometimes ways and means...
posted by Admira at 3:20 PM on July 9, 2009

Best answer: For example, say you have a program (could even be antivirus) that you'd like to change a setting on (like say disable scanning). But the option is greyed out due to system settings (GPO).

Well theres a little program designed to help you out. Its called Windows Enabler. If you run it and turn it on it it will let you enable disabled checkboxes, menu items etc. Be warned, this can caused lots of unexpected things to happen and I can't give any guarantees around what might happen.

Also some corporate antivirus applications are configured to detect utilities like this so YMMV.

Assuming you are talking about a corporate environment, all of the above advice could get you sacked, so read or ask IT for a copy of their computer usage policy and make sure that what you are doing is above board first.
posted by Admira at 3:24 PM on July 9, 2009

delfuego is right, the USB protocol dictates that the device tells the host what it's class ID is so it's stored on the device itself, usually in ROM. And even if you could, changing the class ID to a non-storage class will break the driver. Look elsewhere for your solution.
posted by scalefree at 4:19 PM on July 9, 2009