The standard file-extensions used in WordSmith are
.cnc concordance file
.lst word list
.mut mutual information list
.dcl detailed consistency list
.tokens, .types word list index file
.kws key words file
.kdb key word database file
.ali aligner list
.vwr viewer list
WordSmith does not affect your Windows Registry, unlike most other programs. The reason is because this can make a system slow down and become unstable, and it also means that to remove WordSmith you can simply delete the folder it is in.
In the Controller's General settings, or on installing, however, you can if you wish associate (or disassociate) the current file-types with WordSmith in the Registry. The advantage of association is that Windows will know what Tool to open your data files with.