Microsoft has added a new feature to Windows 7 that keeps the drive hidden when the drive is empty. Use this tip to change the setting and show empty drive in the Computer section along with other drives:
1. Launch File Explorer, under Tools click on Folder Options
2. Select the View tab
3. Uncheck Hide empty drives in the Computer folder
4. Click OK
Put your empty USB stick in USB port to check drive visibility. Thats it.