Save this page locally, to your desktop or hard drive - as "Web Page, HTML-only",
then reopen that local page in a browser to use this tool.
Notice: In case you need to encrypt your Microsoft Word document you can use option to save your document with .xml or .htm name extension first (instead .doc) prior to encryption. Consequently, the decryption will produce your Microsoft Word document in xml or htm format (both supported with new Microsoft Word).
Use of this tool has all benefits of free open source software and in addition this tool use strongest publicly known and approved encryption algorithm ( AES/Rijndeal with 256 bit key ), compared to non disclosed proprietary commercial solution as Microsoft Word integrated encryption option for example.
This document/tool is in the public domain.