BIOS not reachable in laptop: 29 May 2013

[Suramya Rajwade <suramya.rajwade@gmail.com>]

BIOS Version : FUJITSU // Phoenix Technologies Ltd. // Version 1.10 // Release date as 24/05/2012

Other BIOS details : Phoenix SecureCore Tiano (TM), Copyright 1985-2011

FUJITSU Laptop : LH532 L-series lifebook, Core i3 3rd generation, 500 GB harddisk, 4 GB ram

I installed debian wheezy 7.0.0 u1 using netinstall-amd64 through USB, now bios is overwritten by grub2. I am unable to boot from USB, DVD etc. Only booting from harddisk. 

I detached the harddisk but all now available is grub2. If this needs to be posted in alternate forum or relevant guide, kindly provide the link.

Installation : 

1) I provided EFIBOOT partition as 10GB whereas maximum says 256MB.

2) While package installation was happening from network mirrors (cdn.debian.net) I left the machine. When I came back installation was done, taking some default values (if at all).

Queries : 

1) Do I need to flash BIOS, where I can get the relevant .bin file? How to do it? Relevant guide link?.

2) Grub2 : Chainloader, boot, loadbios, fakebios for the required image, does this help? Relevant guide link? Where to find the image (vmlinuz from 1st cd does not work)?

3) Can I boot from USB-netinstall (hd0), to reinstall debian 7.0.0 with different partitioning? I already messed with fdisk, cfdisk, fsck etc.

4) Where can I take care, so that in next installation it does not override the BIOS with GRUB2? Is it in BIOS setting or debian installation?

I am unaware of UEFI if it has to do with it else ignore. Kindly be patient, and thanks for the same.

Thanks,

Suramya