Files compressed by Microsoft's file compression utility can be expanded and searched by the program. Such compressed files can be found on setup disks and have file extensions ending with _. For instance a file such as README.TXT will have the name README.TX_ once it has been compressed. The program automatically checks to see if a file has been compressed by this utility and will expand it if this is the case. If a file has been compressed by any other utility then it will not be expanded and will be treated as an ordinary binary file.