Unable to access Windows Installer service

1. Make sure you did not delete Windows Installer. If you delete it, you'll have to reinstall it.

2. Make sure that the Windows Installer service is not disabled.
View Windows Installer in the services, management tools, Control Panel,
Verify that the settings are not disabled (auto-manually, the default setting should be manual).

3. Please confirm that you did not delete the C:\WINDOWS\Installer folder, if this folder is deleted,
Leads to a series of indeterminate errors, which are likely to be the error you describe.
Because this folder involves a lot of software installation information, the specific solution is unknown.
If you have data recovery software and delete time you can try to recover soon,
Otherwise, uninstalling Windows Installer and reinstalling it may be resolved.

Unable to access Windows Installer service