This article shows you what to do if you get the rewrite.dll failed to load in Windows 10 event viewer for Windows 10 IIS.
Checked Event viewer when my website Showed up with
Service Unavailable 503 error
The Event Viewer Error was
The Module DLL C:\WINDOWS\system32\inetsrv\rewrite.dll failed to load
I went into Add/Remove Programs (Start -> Run-> appwiz.cpl) and simply repaired the following program
IIS Url Rewrite Module 2.0
Afterward, restart your WWW Service in services.msc and your website will now be working. If you are unable to repair the IIS rewrite module using Add/Remove Programs, you will need to redownload them from Microsoft.