Microsoft released the Windows 10 KB4556799 cumulative update on May 12th, and since then, users have been reporting numerous problems trying to install the update. Windows 10 users are facing numerous errors when installing the latest update, and for those who can install it, they are reporting a variety of other problems. With this release, the number of reports has significantly increased, with BleepingComputer receiving more emails than usual about people having trouble. Some people have been able to fix it by disabling the ‘Enable audio enhancements’ option under Windows speaker properties.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-kb4556799-update-wont-install-has-audio-issues-bugs/