After searching for a Floppy drive, I gave up and found a nice way to update the Bios of my Dell computers (Optiplex 755 and 760) right within Ubuntu.
You first have to install the BIOS information tool:
sudo apt-get update
sudo apt-get install smbios-utils
Then, get the System ID:
You will get an output like this: (from my Dell Optiplex 760)
Libsmbios version: 2.2.28
Product Name: OptiPlex 760
Vendor: Dell Inc.
BIOS Version: A12
System ID: 0x027F
Service Tag: 860774J
Express Service Code: xxxxxxxxxxx
Property Ownership Tag:
You will only need the System ID,
go to http://linux.dell.com/repo/firmware/bios-hdrs/ and search for the System ID.
There will be multiple choices, get the one with the BIOS version you want.
Click on it and download the bios.hdr file.
To install the BIOS file, we have to activate the dell update service, (if there is no output, the service is activated)
sudo modprobe dell_rbu
Tell the update tool what to do:
sudo dellBiosUpdate -u -f /place/where/the/bios/is/bios.hdr
You are ready now and can restart the computer. The new BIOS will be installed at the first boot, this can take some time (it took me 5 minutes).
This way, you don’t have to struggle with a floppy disk or a Windows installation.