Bios not recognizing USB in EFI mode

Question

I got a brand new Laptop with pre installed windows OS i wanted to do a clean install Okay so this is what i did i created a bootable USB of windows 8.1 Pro. Then i booted my laptop which was by default in EFI mode which didnt detect my pendrive so i did a google search and the suggestion was to change the bios to legacy mode.

i changed it to legacy mode and the usb was detected i did a clean install successfully but the problem was the clean install changed my laptop hdd to mbr disk.

but i want it to be an gpt installation How do i do it without losing my data.

if conversion without data loss is not possible how to i make sure i do a clean install by making sure it installs to a efi partitioned hdd

I want a gpt drive because the boot time is faster and is less annoying i dont want to see a black screen with a dash which displays for a few seconds.

Please help me out im really frustrated with this two different systems

Solution

Well after experimenting a bit i found the answer to my own question.

If one has to clean install windows 8 and to install on a GPT partitioned hdd , the bios settings must be changed to UEFI mode and only then the installation must begin.

for the bios to recognise ones USB as UEFI device ,the win iso must be installed on the USB as GPT partition. I used a software called Rufus it had the ability to make my pen-drive bootable as UEFI device.

If one has to clean install windows 8 and to install on a legacy(MBR) partitioned hdd , the bios settings must be changed to legacy mode and only then the installation must begin.

Some Bios have the capability of recognising both legacy and UEFI devices hence the setting must be set to both if you don't really care about the partitioning system