The information log file is named "InfoLog.txt" and can be found in the main CatTools installation folder (normally C:\Program files\CatToolsn where n is the version) .
To purge the log file, use the File | Delete | Delete log file menu. Note that you can set a maximum size for this file in the File | Setup logging menu.
If you Click on "Delete log file" then you will get a confirmation window pop up:
"Are you sure you want to delete the log file?"
Click "Yes" to delete the existing log file.
Click "No" to leave the existing log file as is.