It installs unknown device. I have been using this hub for almost 4 years without any issues, then all of a sudden it stops

Method 1 - Unplug Computer So how did I finally fix the problem? Well, if you are lucky, it's a super simple solution! Try this method first and if it works, you'll have saved a lot of time.
Simply unplug your computer from the power supply. Yes that is it! Note that this does not mean just turning off your computer using the power button because most modern computers don't actually turn off completely and the motherboard will still get power. This is useful sometimes if you want to remotely wake up a computer, etc.
The motherboard is where all of hardware of the computer connects to, including the USB ports. Sometimes the motherboard needs to be "rebooted" because things can go wrong, i.e. all or some USB ports suddenly stop working. The small microprocessor on the motherboard will reload the drivers and your USB ports should hopefully be recognizing devices again.
So first turn off your computer using the Shut Down option in Windows or pressing the power button and then UNPLUG the PC from the wall outlet. Let it sit for several minutes and then plug it back in.
Method 2 - Update Device Driver If Windows is not able to recognize the device, you may also see in Device Manager that the device shows up as an "Unknown Device". You can get to Device Manager by clicking on Start and typing in devmgmt.msc or by going to Control Panel and clicking on Device Manager.
In that case, you should right-click on Unknown Device, click on Properties, then the Driver tab and then click Update Driver.

If this doesn't work, you can also try to download the driver for your device from the manufacturer's website. If the USB device is just a flash drive, then it's probably not a driver issue. However, if you are installing a USB printer, drawing pad, etc, then it might be worth downloading the driver for that specific device.

Method 3 - Restart & Disconnect USB Devices The next thing you can try is to disconnect all USB devices and then restart the machine. once you have restarted, try to connect the USB device that was causing the problem.
If that particular USB port doesn't recognize it, try another one. If the device is recognized by a different USB port, there could be a hardware problem with one of the USB ports. If no USB port recognizes the device, then keep reading because it's probably something else.

Method 4 - USB Root Hub Another thing you can try is to open Device Manager, expand USB Serial Bus Controllers, right-click on USB Root Hub and then click on Properties.
Click on the Power Management tab and uncheck the Allow the computer to turn off this device to save power box. If you have more than one USB Root Hub listed, you need to repeat these steps for each one.
Click OK and then restart your computer. Try to reconnect the USB device and see if it is recognized. If not, go back to the power management tab for each one and check the box again. If it does recognize the device, then leave them unchecked.

Method 5 - Connect Directly to PC A friend of mine ran into this issue and the cause ended up being his USB hub. He only had three USB ports on his computer, so he bought a hub where he could connect an additional 8 USB devices.
I guess this proved too much for his computer and it just started sporadically not recognizing various devices. After removing the hub and connecting the device directly to the computer, it worked just fine.
We haven't really been able to find any other solution to this problem other than reducing the number of items connected to the hub. Actually, one other solution worked, but it meant having to buy a new USB hub with more power.
If you are having this problem with Windows 8 or Windows 8.1, then you might be in luck. Microsoft has released a fix for Windows 8 not detecting USB devices properly. Make sure to install this hotfix if running Windows 8.
Method 6 - USB Troubleshooter If nothing has worked so far, you can download the Windows USB Troubleshooter Fixit tool. It's a free tool that works with Windows XP, Vista and 7.
You can either have the troubleshooter fix the problems for you or select the fixes yourself. I would just let it fix them for you since the choices can sometimes be confusing and technical for the novice user.
Method 7 - Update Generic USB Hub If you are getting the Unknown Device error in Device Manager, you can also try one other thing. Open Device Manager and then expand Universal Serial Bus Controllers.
You should see at least one item called Generic USB Hub. On some computers, you might see two, three or more of these. Right-click on the first one and choose Update Driver Software.
When the update dialog pops up, choose Browse my computer for driver software.
When the update dialog pops up, choose Browse my computer for driver software.

You need to install a driver for the device.

This device should be recognized automaticaly by the OS. There are some issues with Windows 7, though.
Make sure you are trying to plug it in a 2. USB port, rather than 1.1. This might cause you trouble (even though this will not be a problem if you have a new computer)
Connect the hub to the external powercord. Sometimes it is not recognized because the hub cannot drain enough energy from the port.
if you are using a desktop pc, make sure it is plugged in the rear usb ports and not at the ones up front.
refer to the manual for further assistance: http://www.dynexproducts.com/cms/documents/DX-B4PORT-B7PORT_09-0962_QSG_V4_ENG_Final_lr.pdf

also include the hub make and model number.....
Generally , an unknown device means that the drivers are not there and windows has thrown it's own generic drivers in . Once they have "unknown" status, the computer thinks they are installed and wont try to install them again UNTIL you go into the device manager and uninstal the drivers denoted by a yellow ! or ?.
hit START-SETTINGS-CONTROL PANEL-doouble click system- select the hardware tab at the top- then select device manager.
Scroll down to "unknown devices" click the plus next to it if it isnt already displayed and uninstall the devices with the yellow marks.
This will make the computer look for new drivers when you restart it.

may i know what device was connected to those ports?try connecting a mouse to the same ports and see whether it is detected.If it works well and fine.Other wise goto Control panel>>System>>Device manager>>Universal Serial Bus Controllers>>Here, delete all the USB Root hubs.If you are removing them using a mouse connected,then u might lose the mouse response after u delete the USB Root hubs.Please note this.Restart the system after deleting all the Root hubs and wait for a few seconds for them to get installed back.Restart again and confirm whether the issue is resolved

Most likely a motherboard problem, though you can try and re-do windows, best bet on getting it all to work is Turn off CPU, Unplug Power cable, And all usb devices, let it sit for about 20mins. Plug it all back in. Turn on the CPU! Though this might really get on your nerves having to do this multiple times, id get a new motherboard.

THE FOLLOWING IS COURTESY OF MICROSOFT Help and Support

When you plug a USB device into a Windows XP-based computer immediately after the computer comes out of standby (S3) or hibernate (S4), the computer may not recognize the USB device. When this issue occurs, the USB device may be listed in Device Manager as an unknown device, and you may receive the following warning message:
Unrecognized device has been found.

This issue occurs because, when the computer comes out of S3 or S4, there is a five- to ten-second period when the selective suspend feature of the USB driver will interfere with detection of a new USB device connection. The time period depends on several factors. This includes the following factors:• Host controller hardware
• Attached hubs
• Attached devices
• USB driver versions
• Support for USB 2.0
• Additional system hardware or configurations that may change the timing
There may be other reasons that a USB device is not detected

Method 1
loadTOCNode(2, 'workaround'); After the computer comes out of S3 or S4, wait five to ten seconds before you plug the USB device into the computer or hub.

Method 2
After the computer comes out of S3 or S4, unplug the USB device, and then plug the device back into the computer or hub.

Method 3
Use the Device Manager to scan for new hardware. Follow these steps: 1. Click Start, click Run, type Devmgmt.msc, and then click OK..
2. On the Action menu, click Scan for hardware changes. This causes Windows to recognize new devices.
3. Close Device Manager and Control Panel.

Method 4
Disable power management of the USB hub.
Note If you perform the following procedure, you may also reduce the battery life on a portable computer.
To disable power management on the USB hub, follow these steps: 1. Click Start, click Run, type devmgmt.msc, and then click OK.
2. Expand the Universal Serial Bus controllers node, and then follow these steps for each USB Root Hub that is listed: a. Right-click the USB Root Hub, and then click Properties.
b. Click the Power Management tab.
c. Click to clear the Allow the computer to turn off this device to save power check box, and then click OK.

SIMILAR PROBLEMS AND SOLUTIONS loadTOCNode(1, 'moreinformation'); For more information about advanced troubleshooting tips for general USB problems, click the following article number to view the article in the Microsoft Knowledge Base: 310575 (http://support.microsoft.com/kb/310575/) Advanced troubleshooting tips for general USB problems in Windows XP For more information about how to troubleshoot unknown devices in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base: 314464 (http://support.microsoft.com/kb/314464/) How to troubleshoot unknown devices that are listed in Device Manager in Windows XP







Try restarting the computer with the device in. Sometimes if you clear the memory that might help (stating the machine without memory then put it back and start it again).

Sounds like a USB issue. Is the device self powered? Did you try plugging in a different USB cable? Is it plugged into a powered hub?

USB 1.1 devices and USB 2 devices can cause issues together on the same bus or port. Try keeping devices separate or plug in just the maudio device. I had issues with USB Network adapters not being seen all the way because there was a older usb 1.1 device on the same hub.

If they work without the the expansion unit, the unit is not passing the power through. Many work this way. Some will work with external power.