To what Sherpya said, let me add that any system file that can't be opened is probably okay, and files that belong to programs you have running at the time of the ClamWin scan are also probably okay. You can use Control-ALT-DELETE every once in a while to see what programs/processes your computer is using. Windows has so **$%$ many of them running, but if you can get familiar with them, you will probably be able to see when something unusual is running.
If you would like to know something about a file, just do a Google search on the complete file name. The following link, http://www.processlibrary.com/
is also a good place to check the names of files or processes to find out more about them.