Here is a quote from someone who had the same error as you:

I got that error and had to reinstall Crystal for .Net (make sure all check
boxes are checked for Crystal components to install). That fixed it for me.

Also, it's hard to tell if the deleting of the default web site had anything to do with it.

>Cathi,
>I have already attempted that and it wasnt successful. So I followed the instructions on that article and reinstalled Crystal - still throwing the error! I am wondering whether the deletion of the 'default web site' had some negative impact on this situation. I did try to recreate a "Default Web Site" and create the virtual directory in it. I am still baffled :S.
>Any other suggestions?