Found this online . You might want to try this :
I discovered that the Reporting Services Configuration Manager was incorrectly showing green check-marks indicating my Report Server and Report Manager Virtual Directories were set up, when in fact they were not (what tipped me off to this is when I went to Control Panel -> Administrative Tools -> Internet Information Services, there were no Report Server or Reports folder branches under my Default Web Site tree). So in the Reporting Services Configuration Manager, I clicked the New button to create the default Report Server and Report Manager Virtual Directories ((this was the 2nd time I did this, which may have been necessary because I uninstalled and reinstalled IIS after instaling SSRS). This time the IIS manager showed Report Server and Reports folder branches under my Default Web Site tree, and I was able to successfully browse to http://localhost/reportserver, AND deploy my SSRS project to the web server. Note that I am running a named instance of SQL Server 2005 (the default instance is SQL Server 2000), and even though I have seen posts suggesting the correct URL for a named instance would be http://localhost/reportserver$<named_instance>, this did NOT work for me ... http://localhost/reportserver DOES work.