It’s been a long time, I know, but I have been quite busy. When I get an idea about writing something here, I always say I will do that tonight. And tonight comes and tonight goes and I don’t write anything. So this time I had this little problem, found a obscure fix, and decided to write about it now, or else I would not do it. So here it is.

I have an desktop application that uses the AppUpdater component to install updates on all client machines. Somewhere, a long time ago, I found that I needed to enable WebDAV on the IIS server hsoting the updates.

A few months ago I moved the application to another server, with 64-bit Windows installed, and apparently everything was working fine. Until tow days ago.

I installed a web service (ASP.NET) application, and it wouldn’t work until I changed IIS to work on 32-bit mode unde 64-bit Windows. I already had learned this with another server migration, so I got it to work in a few minutes.

Today I released a new version of the client application, and I got an error message from the AppUpdater component saying it couldn’t update the application because a network error had occurred, and the web server had returned 501 - Not Implemented.

I remembered the WebDAV thing and immediately checked for it, and it was Enabled.

To make a long story short, after some time googling for this problem, I found a thread in a discussion forum that seemed to talk about this problem and offer a solution. The steps basically are:

  1. Have IIS runing in 32-bit mode under 64-bit Windows
  2. Go to IIS Management Console, to the Web Service Extensions section
  3. Add a new web service extension, naming it WebDAV2 (or whatever you want) and adding this file as required: 
    C:\WINDOWS\SysWOW64\inetsrv\httpext.dll
  4. Enable that new WebDAV2 extension

And, I don’t know why, it worked!