Hi Nir212,
· Have you made any changes on the computer prior to this issue?
· Do you get any error message or an error code?
Follow these methods.
Method 1: Run the hardware and device troubleshooter.
http://windows.microsoft.com/en-us/windows7/Open-the-Hardware-and-Devices-troubleshooter
Method 2: Uninstall and reinstall all USB controllers. Follow the steps:
a) Click Start, type device manager on the search box and press enter.
b) Device manager window will open, expand Universal Serial Bus controllers.
c) Right-click every device under the Universal Serial Bus controllers node, and then click Uninstall to remove them one at a time.
d) Restart the computer, windows will reinstall the USB controllers.
e) Plug in the removable USB storage device, and then test to make sure that the issue is resolved.
Method 3: Put the computer in clean boot state to see if there is any software conflict as clean boot helps to eliminate software conflicts.
Note: After clean boot troubleshooting steps, follow Step 7 in the link to return the computer to Normal startup mode.
Method 4: Also try connecting the device with a different USB port on the computer.
Make sure you have the latest windows update installed on the computer.
Install Windows updates in Windows 7
Also install the latest chipset drivers from the manufacturer’s website.
http://windows.microsoft.com/en-us/windows7/Update-a-driver-for-hardware-that-isnt-working-properly