How come the Windows is unable to start when an external USB drive is connected to the VAIO computer?

When connecting to an external USB drive (for example MO drive, Hard Disk Drive) to the VAIO computer, a black screen is displayed in the middle of starting Windows.

Please check the BIOS setting with the steps below when this symptom occurs:

1. Start the computer and when the SONY logo appears, press F2.
2. Select Boot from the BIOS Setup Utility screen.
3. Select 2. Removable Drive and press Enter.
4. When the pop-up dialog appears, select Disable and press Enter.
5. Select Exit, choose Exit Saving Changes and press Enter.
6. When Setup Confirmation dialog appears, select Yes and press Enter.

Note:
- After setting of BIOS with the steps above, the VAIO computer will not be able to start with the USB floppy disk drive (PCVA-UFD1, PCVA-UFD2). However, when the computer successfully logs into Windows, the USB floppy disk drive can be used as normal. In order to enable the computer can be started with the USB floppy disk drive, USB FDD must be selected in Step 3 of the above BIOS setting.
- The mouse function cannot be used in the BIOS setting Utility. Please use the cursor key to navigate.