Problem:

You were applying Windows updates to a Windows server and got an error with code 0x8007000d or 0x80073701. You tried restarting your server several times but it seemed that the problem still persisted.

0x80073701 = ERROR_SXS_ASSEMBLY_MISSING which means there are some system files are missing, which caused the update installation failure.

Solution:

1. Restart your server.

2. Open Command Prompt (Admin).

3. Execute the commands below.

net stop wuauserv
net stop bits
:: Removes all files from the directory
del /q C:\Windows\SoftwareDistribution\*
:: Recursively removes all nested directories
for /d %x in (C:\Windows\SoftwareDistribution\*) do @rd /s /q "%x"
net start bits
net start wuauserv
control update

4. Close the Command Prompt (Admin).

5. Install Windows updates.

6. Click Retry button if you encounter an error.