It is present under:
C:\Windows\System32
Open Command Prompt as Admin and run the following command:
sfc /scannow
Once done then :
Run the DISM command. Using DISM, you can specify a Windows image to use to replace the missing file. Basically, you download the W10 ISO, then run the command pointing to it.
You could try this command first, (at an admin command prompt), and if it gives an error, grab a W10 ISO and try the second command below:
Dism /Online /Cleanup-Image /RestoreHealth
Alternatively you can download the missing Dll file and put it under C:\Windows\System32
or, from here