ASP.NET MVC site takes too much time to load probably because of a Windows service running on the same server

I have a dedicated Windows 2008 server with several websites and 1 windows service running.

The service runs every 30 seconds and is pretty CPU intensive. However all sites are loaded really fast except for the one that is closely connected with the service. This website project dll is referenced from the service, and I think this is the reason it is so slow.

Has anyone had any experience with this? How can I improve the loading time of the site?

Update

Here's more information:

Only the first time load is slow. Subsequent loads are fast. The website and the service access the same MongoDB database. The service also references the website's dll and uses a lot of classes including UsersRepository.

Stopping the service makes th开发者_运维技巧e application run normal.

Yes, it was the service's fault. I solved the problem by making a clone of the bin folder which is used for the service only.