Great post! Should help others.
Hi Everyone, Found a solution to install BIOS 1.1.18 on a Windows 11 OS build. This BIOS version was not installing via the DELL SupportAssist tool or using a CMD prompt and /forceit option on the BIOS executable from a local hard drive. XPS8930_1.1.18.exe /forceit   (Run as administrator) Solution 1. Build a Windows 11 bootable USB drive that contains an EFI partition.  Here are some great instructions. I used the Windows 11 Media Creation Tool method. [URL]  2. Copy the BIOS 1.1.18 exe file (XPS8930_1.1.18.exe) to the USB drive, having downloaded it manually from DELL drivers & downloads for your computer. Place file in top (root) directory for ease of future access. [IMAGE] 3. Restart the computer. 4. Press F2 to boot into the BOOT SETUP screen and make sure:      Enable USB Boot Support is [Enabled] [IMAGE]   5. Restart the computer. 6. Press F12 to boot into the SETUP screen, using the keyboard select:     BIOS Flash Update [IMAGE]   7. Using the keyboard tab and arrow keys (I couldn't get any mouse to be recognized), browse to the directory where you coped the BIOS update file on the Windows 11 bootable USB drive. 8. Tab down and select the BIOS 1.1.18 update file:     XPS8930_1.1.18.exe 9. Tab down and select the button:     Flash Upgrade  [IMAGE]   9. The BIOS 1.1.18 will now run to completion, at least it did for me using this method.   Note:  To recognize the USB drive via the BIOS Setup screens, Windows 11 requires it to have a bootable EFI partition.  Without being bootable with an EFI partition, the USB drive is not recognized by the Flash Update feature. Hoping this helps someone in the same situation. Aly    
XPS 8930, Windows 11, BIOS 1.1.18 not installing FIXED