Helping people with computers... one answer at a time.
Older computers may have only the slower USB 1.1 interface. Adding USB 2.0 isn't difficult, but it does require a hardware addition.
My computer apparently has only USB 1.1. Is there a download or something to upgrade to 2.0? What do I need? Will I hurt anything if I plug in a USB 2.0 device to my USB 1.1 socket?
Unfortunately, upgrading from USB 1.1 to 2.0 requires more than software; it actually requires new hardware.
The good news is that the hardware is typically inexpensive. In addition, depending on the 2.0 device, it's possible, though not guaranteed, that it'll work just fine with your 1.1 interface.
But it certainly won't hurt anything to try.
Let me explain...
The biggest visible difference between USB 1.1 and 2.0 is that 2.0 is faster.
The biggest invisible difference is that a USB 2.0 interface requires different hardware - hardware that is capable of the higher speeds that USB 2.0 supports.
So, to "upgrade" from 1.1 to 2.0 typically isn't a software upgrade at all; it's an addition of hardware. For desktop machines you can purchase a relatively inexpensive USB 2.0 interface that you add to your machine. For your laptop you'll probably purchase a PCMCIA card that adds a USB 2.0 interface.
In either case, if the machine already had a 1.1 interface, that's still there, and still runs at 1.1 speeds. The old interface is still perfect for devices that don't require the speed supported by 2.0. The new interface then can support the higher-speed devices.
Now, a 2.0-capable USB device doesn't necessarily require USB 2.0. A great example is the Maxtor external USB drives I use for backup. If I plug them into a computer with only a USB 1.1 interface, they work just fine. They're slower, much slower in fact, but they do work well.
In most cases, in that situation, about the worst that will happen, besides the slower performance, is that Windows may pop-up a message indicating that "this device could perform better if plugged into a USB 2.0 interface". Which is quite true, and otherwise benign.
That's not true for all USB 2.0 devices. Some specifically require a USB 2.0 interface because they require the faster data rates. But again, plugging them into a 1.1 interface won't damage anything. The software supporting a device that requires 2.0 should simply report that the device won't work or that some features may be disabled. At worst, the device won't work or some features may be disabled - without any warning.
A final note on USB cables: Cables are not devices and aren't "recognized" by USB interfaces or devices. Plug just a USB cable into a computer's USB interface and nothing will happen until you plug a USB device at the other end of the cable.
USB 1.1 and 2.0 cables are essentially identical. The difference is simply that the USB 2.0 cables are of a higher quality required to support the higher data rates possible with 2.0. You can safely use a 2.0 cable for any USB application. You can probably use a cable marked as 1.1 for many 2.0 devices. I certainly have, but if you experience problems, replacing it with a cable rated for USB 2.0 would be one of my first steps.