That was a tad careless. You should be able to retrieve any default files from the CD. Alternatively try a duplicate install of CFS2.
DUPLICATE INSTALL of CFS2 (or any other MS sim)
To do this, simply rename the existing CFS2 root directory folder to any other name.
Then insert the CD & install in the usual way.
You will now have two separate versions of CFS2 which will run independently.