Hello Inna, Michael,
There would not be a problem to run Sitefinity on server 2008. It seems this is an issue related to the server configuration. I am sending you some screenshots with configuration settings on my local server 2008 where I managed to install Sitefinity.
If you cannot set up Sitefinity at your end, please open a support ticket and we could schedule a web conference or remote desktop to your server.
All the best,
the Telerik team
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