Restart your computer. Then open QuickBooks Desktop.
If you are prompted to install an update, select Install Now.
If you are still unable to install the update, delete and download the update again.
Close QuickBooks Desktop.
Go to C:\Documents and Settings\All Users\Application Data\Intuit\QuickBooks < versionXX> \Components. (Note: xx is the version number of QuickBooks Desktop. For example, QuickBooks Desktop 2019 is DownloadQB19.)
Open QuickBooks Desktop. Then go to the Help menu, then Update QuickBooks Desktop.
Go to the Update Now tab. Then mark the Reset the updates checkbox.
Select Get Updates to redownload the updates.
When the download is complete, close and reopen QuickBooks Desktop.
On the QuickBooks Desktop Update Service window, select Install Now.