From: ZUC on
Hi all,
I'd like to ask you a question about a strange behaviour that I'm
getting from a customer's server.

Environment: Windows Server 2008 R2 Standard, IIS 7.5. Like 50
websites installed using ASP 3, 3.5 and PHP 5 languages. This
server is behind a firewall so it has a private IP address like Firewall is set to NAT public IPs to the private IP of this

Each site has its own application pool configured in this way:

Problem: a simple ASP page like this one:
The page called via XmlHttp is on the SAME SERVER (http://

I noticed that the page, when called, creates a loop and freezes the
entire pool.
The only way to restore the website is to recycle the application
[also .CreateMHTMLBody method from CDOSYS library had the same

At first time I thought it was a network problem so I added a NAT
Loopback rule on the firewall. After that, I could browse each website
using IE on the server, so routing/networking was OK.

Then I thought it was a problem of XML component, I checked and I
noticed that the page was using "Microsoft.XMLHttp" component. I
switched it to "MSXML2.ServerXMLHTTP". No luck.
Components installed on this server are:

I lost a few days trying to solve this issue, that I tried to disable
32bit support from that application pool and.... ta-dah! It started

Now, the question for you is: what's the connection between IIS 7.5 -
Application Pools - ASP - Xml and that setting??
I'm speking about this fu**ing checkbox:

Thank you for your answers,
have a nice day!
From: ZUC on
OK, i tried many methods in order to solve keeping 32bit support on
the application pool.
The only way it worked was setting the number of IIS Worker Processes
from 1 (default) to a higher level (e.g. 5)

Now I have a web garden instead of a pool, but now it works :)