I see a lot of different options here, so:
A) Depending on your requirements for updating/rendering the HTML files, you might consider a hosting option? there a plenty of cheap hosting sites and those running Apache can run HTML files too.
B) If you need secure access (protected), you could also consider a cloudbased hosting, such as Amazons Cloudservices. This could also be used for option A)
C) How about direct file access for the users? Just leaving them with READ ONLY access to the server folder?
D) Put the pages inside a Google Docs account. Then share the content to a certain group. This will give you Documents, Spreadsheets and Presentations. You could uploade the changes from Office files or PDF too.
E) Build a small service from one of the free samples on the net.
I have a few in Microsoft.NET, I'll have a search at Google for some of them:
even more here:
It ought to be easy to translate the code into a .net NT service afterwards.
Does any of my options solve your request?