IIS7 Slow Problem

Hello,
We are facing problem with IIS7 under Windows 7, our local website is too slow and sometimes timed out but when we were using IIS5.1 under WinXP we didn't face any performance issue. I search around this issue and it look like a lot of people are facing the same thing and someone suggest to modify the connection string but this also didn't work until I tried to create a demo that doesn't have any database or connection string but just few pages and navigation between them and I faced the slow issue too, also I tried to modify the application pool to be Classic .Net, and I tried to modify the folder security to be full control to Everyone but neither of those worked.

I don't know how to deal with this and I hope that someone give me the right answer.

Thanks in Advance.

I don't often point people to other sites, but you may be better asking here - Forums : The Official Microsoft IIS Site

Personally I would run it on Server 2008 if it is for production, especially customer facing.