New Installation on a clean Servers:

I have configured two clean servers for testing nopCommerce:

The first server is running Windows Server 2008 (Web) with IIS enabled.
The second server is running Windows Server 2008 (Standard) with SQL Server 2008.

I downloaded the (non-source) version, extracted the files and installed them under C:\inetpub\wwwroot. When I try to run the installer, as per the documentation I get the following:

Server Error

500 - Internal server error.
There is a problem with the resource you  are looking for, and it cannot be displayed.

Thanks,
j-parker

Follow these steps:

1.) Use this server second server is running Windows Server 2008 (Standard) with SQL Server 2008.

2.) Open database and create a database (Only create a database you don't need to create any tables).

3.) Now extract all files from (non-source) version

4.) Put them into C:\inetpub\wwwroot

5.) Make sure IIS is running

6.) Try to open the website in your web browser

I hope you will see installation screen

let me know if it doesn't work

Regards,
Adil

Thanks Adil,

I did as you suggested and got the following error:

HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid. Detailed Error Information

Module IIS Web Core
Notification BeginRequest
Handler Not yet determined
Error Code 0x80070021
Config Error This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false".  
Config File \\?\C:\inetpub\wwwroot\web.config
Requested URL http://localhost:80/install/install.aspx
Physical Path C:\inetpub\wwwroot\install\install.aspx
Logon Method Not yet determined
Logon User Not yet determined

Config Source
  204:     </modules>
  205:     <handlers>
  206:       <remove name="WebServiceHandlerFactory-Integrated"/>
Links and More InformationThis error occurs when there is a problem reading the configuration file for the Web server or Web application. In some cases, the event logs may contain more information about what caused this error.
View more information »

Thanks again,
j-parker

there is a number of reasons why this error can occur; if you search the Internet with "HTTP Error 500.19" and the error code, you might find the answer that fits your scenario in one of the posts