500 - Internal server error on installation

Hello.

I have tried several times to install nopCommerce but with no luck.

Whatever i do i get a 500 - Internal server error on installation and installation doesn't even start.

I run the Application under IIS 7.5 with windows server 2008 R2.
The app has it's own AppPool in Integrated Mode and target framework v4.0.30319

What is wrong?
Please help.

Can anyone please help?

same issue here.  Be sure you are running ASP 4.0 and have the correct permissions.

Did you solve it?
And if so, how?

How am I going to be sure that I'm having required permissions?
On the same server there are also other sites that are running (.net 3.5)