Hi, I'm Robinson, and I’m happy to help you today.
I know how frustrating this may be for you but I'll do my very best to help you.
You can disable the UAC in the registry editor.
1-Right-click on Start and select Run
2-Type: regedit and click on Ok
3-Go to the Key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
4-Double-click on the EnableLUA and change the value to 0
5-Reboot you computer
After that, you should be able to run the repairs without the UAC screen.
Check if doesn't have any corrupt files on the windows.
1-Right-Click on Start then click on Windows Powershell (admin)
2- Type these commands.
sfc /scannow (and press Enter)
Dism /Online /Cleanup-Image /ScanHealth (and press Enter)
Dism /Online /Cleanup-Image /CheckHealth (and press Enter)
3- The DISM tool will report whether the image is healthy, repairable, or non-repairable. If the image is repairable, you can use the /RestoreHealth (Dism /Online /Cleanup-Image /RestoreHealth) argument to repair the image.
Then you can use this command to repair the registry entry for the UAC setting.
1-Press Win+x
2-Click on "Windows Powershell(admin)"
3-Type this command:
REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\7516b95f-f776-4464-8c53-06167f40cc99\8EC4B3A5-6868-48c2-BE75-4F3044BE88A7 /V Attributes /T REG_DWORD /D 1 /F
4- Press Enter