Windows Update keeps offering same update

Windows 7 tells me I have an update to perform. I have installed the update and it says it installed correctly. Minutes later it says I have the same update to perform. I installed same update 5 times. Then I looked in "latest updates and find that there has not been a successful update for 10 days. I ran a windows repair and it says," Service Registration is Missing or Corrupt." Also says, "Win Update Error: 0x80070490(2018-04-17-T-05-00-52P). The Repair could not fix either of these problems. Does anyone know what they are or how to fix them??

Follow the steps below:

1. Repair damaged system files

• Open search and type cmd.
• Right-click on the Command Prompt option and select Run as Administrator.
• Type sfc /scannow command in the run dialogue box and press Enter.
• Let the system perform the repair automatically. If possible, restart your PC after that and try to run Windows Update now.

2. Use Deployment Image Servicing and Management (DISM) tool

• Open search and type cmd.
• Right-click on the Command Prompt option and select Run as Administrator.
• Type DISM.exe /Online /Cleanup-image /Restorehealth command in the run dialogue box and press Enter. In case your Windows Update client is damaged, run the following command instead: DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:C:\RepairSource\Windows /LimitAccess.

Reference: How to Fix Windows Update Error Code 0x80070490?