I Need To Reinstall Windows On My Dell Oxtiplex 780 But I Have Lost The Recovery Partition Is There Anyway I Can Create A Recovery USB / DVD To Do A Clean Install of Windows ?
Once the factory installed Recovery partition is deleted, unfortunately it cannot be recreated.
You will need either a Dell reinstallation disc, that's the same version factory installed, or buy a new retail, or OEM version of windows, that has it's own COA/product key
Which version of windows are you using?
If your Windows 7 can boot, then update your BIOS to the latest version:
Then proceed with the Upgrade to Windows 10:
After the initial upgrade you can download Windows 10 Installation Media and Clean Reinstall: