I have been using IIS for over ten years now, and it knows a lot about changes in your content and serves the latest versions. You do not need to update it. Some files, such as web.config or global.asa, are special, and when they change, IIS automatically reloads the site for you.
Mig types such as html, txt, gif and jpeg are considered proxy servers and browsers very static and are aggressively cached in these layers (vs asp, jsp, etc.).
This superuser question is talking about updating in Chrome - apparently this is not always easy.
If, however, you want to give IIS the easiest command line method:
iisreset
I doubt this will fix your problem, but it may make you feel better :)
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