Sony USM2GL MicroVault Click 2GB USB Flash Drive

Hi,

1. Which operating system is installed on the computer?
2. Did you make any changes to the computer prior to the issue?

Check if the same USB gets detected on the different computer or check if different USB gets detected on this computer.

Method 1
I would suggest you to run the fixit from the following link:

Hardware devices are not working or are not detected in Windows
http://support.microsoft.com/mats/hardware_device_problems/en-us

Method 2: Remove and reinstall all USB controllers.

To remove and reinstall all USB controllers, follow these steps:

a. Click Start, click Run, type sysdm.cpl in the Open box, and then click OK.
b. Click the Hardware tab.
c. Click the Device Manager button.
d. Expand Universal Serial Bus controllers.
e. Right-click every device under the Universal Serial Bus controllers node, and then click Uninstall to remove them one at a time.
f. Restart the computer, and then reinstall the USB controllers. Restarting the computer should install the drivers automatically.
g. Plug in the removable USB storage device, and then test to make sure that the issue is resolved.

Method 3: Check if the device is getting detected on device manager.
Refer: http://windows.microsoft.com/en-US/windows7/Open-Device-Manager

Method 4: Check if you can access the device through disk manager.

a. Click on start button, type diskmgmt.msc and press enter to open disk manager.