You installed SQL Server 2005 Reporting Services (SP1, SP2, doesn’t matter) with the optional Report Manager web application and opening "http://servername/Reports/Pages/Folder.aspx" with the browser results in "The request failed with HTTP status 400: Bad Request."
Don’t loose hope!
If you’re local, right-click and view the source code of the page. There’s a StackTrace META element.
If you’re remote, go and check the LogFiles directory in "MSSQL.2Reporting Services" or "MSSQL.3Reporting Services" (or similar) in the SQL Server installation directory. Check the most recent ReportServerWebApp__datetime.log file. The stack trace should be at the end of that file.
The stack trace probably reads like this:
System.Net.WebException: The request failed with HTTP status 400: Bad Request.
at Microsoft.SqlServer.ReportingServices2005.RSConnection.IsSecureMethod(String methodname)
at Microsoft.ReportingServices.UI.ReportingPage.EnsureHttpsLevel(HttpsLevel level)
at Microsoft.ReportingServices.UI.ReportingPage.ReportingPage_Init(Object sender, EventArgs args)
Now go and check your %systemroot%system32LogFilesHTTPERRhttperr1.log (or similar) file. At the end, there will be something like
2007-03-12 15:49:30 127.0.0.1 3628 127.0.0.1 80 HTTP/1.1 POST /ReportServer/ReportService2005.asmx 400 – Hostname –
This tells you that IIS rejected 127.0.0.1 as hostname. Which means your server is multi-homed and you haven’t associated IIS’s Default Web Site with 127.0.0.1 (localhost). This could help. So does using "(All interfaces)". But, I don’t know. I haven’t tried messing with the Default Web Site on my server. (I fear IT would come after me and do bad things to me if I did.)
Note: Reporting Service might be configured to use a different web site than Default Web Site.
I suggest to change the Report Manager web site application configuration RSWebApplication.config in your "Reporting ServicesReportManager" directory.
Make a backup copy first. Then set the value of the ReportServerUrl element to http://servername/ReportServer and delete the value in the ReportServerVirtualDirectory element. (These elements are mutually exclusive. If Reports fails to start with a yellow screen of death complaining that ReportServerUrl is not a configuration setting, delete on of them element values, willya?)
Then start and stop the "ReportServer" application pool (or whatever the application pool is for your Report web). (Don’t restart IIS unless you’re in your scheduled downtime window.)
Now the sun should shine and the world should be a better place.