Martin - Can I just reinstall SSRS and not override anything else? How would I do that? I did not do the original install and don't want to alter anything that shouldn't be. Do you know if a restart will be required?
You could, provided that you don't want the existing installation or anything contained within it. I would recommend that you make a backup of the ReportServer database before you do.
To install/reinstall/repair SSRS, run the SQL Server setup utility and choose the advanced or custom option which will allow you to choose only the components you wish to install.
A restart will probably be required when the installation is complete.