Bios Upgrade Missed Up My Laptop

[DrAboody]

Hello

i just bought an Used HP Elitebook 2740p it was working fine for one week until i unfortunately decided to perform a Driver upgrade including the BIOS

Some weird stuff start to happen after i performed the BIOS Upgrade for example :

*At first i couldn't boot to Windows at all and always show me INACCESSIBLE_BOOT_DEVICE error 

*The boot option menu is empty and i can't boot to any other device in case if i want to install a new OS

So i improvised in order to fix the problem, First i reinstalled the battery and then restored the Bios sittings to default.. Guess what.. It WORKED!!! 😀

Unfortunately a whole bunch of new issues popped up 😔

* The laptop restart 2-3 times before i can actually log in to Windows
* The boot option menu still empty
* The screen blinking before and after log in to Windows
* It takes long time to boot even that i have a very good specs [Core i5, 8GB Ram]
* Mouse pad is not working in fact every time i touches it the pointer just disappear

Thats what i noticed so far.. I will attach a photo for my system information in email if u want

Troubleshooting steps taken:

* Reintalling the Battary a few times allow my laptop to log in to OS

* Mouse Pad now working after i reinstall the driver
* No more restarts after i shutdown the laptop for a few times

[not sure if it will not come back though]
* i still have problem with the screen blinking and the boot option menu

[[i have some photos and a video here that well help u to understand the issue]]

Please if there are any solution or explanation for this issue i will be so glad to hear it

Thanks a lot