Hi Naveen,
If your computer is set to first attempt to boot to another device, this may cause issues with successfully booting to Windows. To reset your computer's BIOS to factory defaults, perform the following steps:
- Restart the computer.
- At the manufacturer's logo during restart, tap the F2 key repeatedly until you see Entering Setup in the top right corner of the screen.
- Depending on the BIOS, you may need to press a key listed at the bottom of the screen to load default settings. For example, F9 on the Inspiron N5110.
- Press ESC to exit the BIOS, and be sure to select Save and Exit to save your changes.
You may also refer to: BIOS: frequently asked questions
Hope this helps.