Welcome to the Dell Community  @rabinniroula 

Reset the CMOS/BIOS.

Dell Latitude E5440 Series Owner's Manual:

https://www.dell.com/support/manuals/us/en/04/latitude-e5440-laptop/delllatitudee5440_om-v2/removing-the-coin-cell-battery?guid=guid-ed299c41-a21a-47ad-a58d-d0ca064eb299&lang=en-us

After disconnecting the CMOS/BIOS battery hold down the power button for 10-15 seconds.

Reassemble and test.

Best regards,

U2

Hi rabinniroula, 

What is the error while downloading BIOS? Have you tried installing it from our Support website if not you can try it using the given link https://www.dell.com/support/home/us/en/04/drivers/driversdetails?driverid=7d7x7.

You can also try to perform flea power to make sure any static charges are removed from the system and try the BIOS update. The link has the steps to perform flea power https://www.dell.com/support/manuals/us/en/04/alienware-aurora-r7-desktop/alienware-aurora-r7-sm/flea-power-release?guid=guid-7d80d88d-9901-4836-a292-7991cc96a7dd&lang=en-us.

Performing flea power will also help with the black screen issue. You can download the video drivers and update once the BIOS update is done. Find the link https://www.dell.com/support/home/us/en/04/product-support/product/latitude-e5440-laptop/drivers

No, that didn't work, neither did removing cmos battery and pressing the power button for 15 seconds. It has driven me crazy.

Hai.

I have tried all that, nothing seems to be working