Sorry, I won't be able to help you with install disks as mine only go up to Pro.
However, this looks like you can download the English ISO for either 32 or 64 bit Ultimate -
https://tech-latest.com/download-windows-7-iso/?nowprocket=1Select Save on the download.
You can also download this tool to create a bootable USB from the ISO -
https://www.techspot.com/downloads/4911-windows-7-usb-dvd-download-tool.htmlYou will need to use an USB because of the size of the file as it will be too big for a DVD.
You won't be able to perform a repair install if you don't have a valid retail key but you can boot up with the USB and select Repair your computer.
As it's an Ultimate version I would think that booting up with an USB should be an option - my Win 7 Home Premium machine only gives the DVD option.
After booting up with the USB navigate to select Command Prompt and enter these cmds -
bcdedit |find "osdevice"
For clarity, that is a Pipe symbol before find and is the uppercase of \
Using your partition letter instead of the X I have exampled, enter -
sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows
Enter exit to close the cmd window when done, remove the USB and shut down.
You can then see if F8 gives the full start up options.
You can also perform a sfc /scannow in normal mode to see if it still finds corruption it is unable to repair.
PM stands for Private Message.
When you click on my user name you will see the option for sending a PM to me.