If you do not have access to old Microsoft Works, it can be really tricky to convert the old .wps documents to something else. Some word processors may still support this format and re-save it to multitude of other document formats, or even plain text files.
You may also find dedicated text converters, or even specialized Works converters, but those generally save to RTF, because this format can be further converted to many other formats.Open WPS file Open TXT file
A text format conversion utility
Word processor and text editor from OpenOffice.org suite
One of the most popular word processor program from Microsoft Office suite
An older office and productivity suite for Windows