Does USB 2.0 & USB 1.1 work interchangeably?

You may have heard that USB 2.0 is "backward-compatible" with USB 1.0/1.1 (Full-Speed USB). We’ll that's true, USB 1.1 is also forward-compatible with USB 2.0. Whenever a system has USB 2.0 ports, you'll find the "Enhanced" USB controller in Device Manager, but you will also find two other USB controllers. These two to maintain backward compatibility to USB 1.1 devices. Each USB 2.0 host actually has 3 chips onboard. The USB controller routes signals to the correct controller chip depending on how a device is recognized. Where a device is physically plugged in has no bearing on how it is routed. All ports on a USB 2.0 motherboard can host any USB devices at all as long as the system and devices are healthy.

The vast majority of USB 2.0 devices will work on older PCs and Macs. None should flat-out fail unless there are other issues with the system. Hi-Speed USB devices will revert to Full-Speed operation when connected this way. Understand that Hi-Speed is at least ten times faster than Full-Speed in actual operation, so the speed difference is quite noticeable - unless you have never experienced Hi-Speed, of course.

When it comes to USB hub compatibility between USB 2.0 and USB 1.1, here some facts: · A powered hub is always preferable to unpowered.

1. USB hub ports are not as capable or flexible as real PC ports so it's best not to expect the world of them.
2. USB 1.1 (obsolete) hubs will work fine on USB 2.0 ports, but they cannot utilize USB 2.0 capabilities. They will default to slower speeds.
3. Hi-Speed and Full/Low-Speed USB devices can coexist nicely on USB 2.0 hubs. Connecting such a hub to a USB 2.0 port is recommended.
4. USB 2.0 hubs can be used on older USB 1.1 computers.
5. Although it is said that you can "cascade" up to 4 hubs, problems may start to arise after two hubs, it's best to minimize hub usage if possible.
6. Many USB devices don't work well on hubs. Cameras, scanners and especially USB drives are known to have problems with hub connectivity. Remember that "active USB extensions" are really just one-port hubs.

How to troubleshoot USB "unknown device" error in Device Manager?

The USB usually comes in with different software for the adding the device onto a computer. But usually it will indicate that the device install in not working properly or unknown devices. To solve this problem with USB port just follow the tips stated below:

• The USB device or the USB adapter requires its own power source. If your USB device or adapter came with an AC power "brick", try re-connecting it.
• Here's a likely one - the front USB ports on your PC case may be misconnected. We have seen them that way from the factory. It's a good idea to check the connections against specifications. The standard order of connection is Red, White, Green, and Black. No more than 4 wires per USB bank are needed.
• Defective device. Do not assume that all PC components work correctly out of the box. I've seen many new USB devices that do not work. If you can, try the device on another PC.
• All drivers are not installed. Some devices will require installing the driver package before plugging in the device. Some devices will also require basic USB files from the Windows CD before the unit will function. The general rule is to always follow installation directions precisely and to have the Windows CD ready.

Hope this short USB problem solving method will help. but if you know other ways to tweak the USB care to drop a comment below.