Cant boot from USB in Vaio laptop

[samnaction]

- Vaio E Series VPCEG18FA
- Model PCG-61911W
- BIOS Version R022028

The laptop says 'Operating System Not Found' . Here is the list of things I have tried :

1. Thought hard disk died ---> But BIOS shows Hard Disk Drive 500GB
2. Tried to install OS

2.1 To access BIOS need to press ASSIST but it didnt work so pressed F2 to enter bios. Unfortunately none of the other functions like boot option or Windows Repair (F8) doesnot work.
2.2 Changed the boot priority to external disk

2.3 Still could not boot in to USB

3. Thought the bios is UEFI instead of legacy

3.1 Couldnt find function in bios to change to legacy

3.2 Still made a UEFI bootable pendrive using RUFUS (this time copied UBUNTU 12.04 since i dont UEFI supported windows iso
3.3 Still nothing.

Other things I have tried :

Changed boot order to network boot and then external disk. It went to network boot and later displays Operating System Not found.

Tried all the three USB port

BIOS is insyde h2 . It takes 5 mins to get into bios or to display Operating System Not found from the VAIO logo.

BIOS updates settings and date/time everytime i boot into it. Tried setting password also.

[MgdElislam]

first, to enter bios in Sony, you have to power-on the laptop, then do a force shutdown power-off by press on power button for 5 second (this is must)
when it power-off, then press ASSIST button

2nd, about boot a usb disk, some models has an USB 3.0 ports that work from chipset other than the main one, and those need a driver to work -but this in windows-. what about in post ? yes, there will be an option in BIOS to let these usb port to work as legacy before windows start , you have to chose these option.

try again, and if you want more help you can attach screenshots of your bios