Decryption specialists PSW-soft's Guaranteed Word Decrypter (GuaWord) is a simple command-line utility for decrypting DOC files used in Microsoft's Word 97 and 2000 and Word XP, 2002, and 2003 in its default (40-bit) mode. It won't decrypt files from Word versions prior to 97, French versions of Word, Word files using newer 128-bit or 256-bit encryption, or other passwords such as read-only passwords; the developer offers other tools for those jobs. It doesn't recover passwords, either; it simply removes them. But for opening compatible Word files, it's a fine tool, if a bit old-school.
GuaWord's executable file is completely portable and requires no installation to use. We downloaded and extracted the zipped package, which includes detailed instructions in the ReadMe file as well as the program's executable file and another program, a utility that taps the processing power of Nvidia CUDA-capable graphics cards to accelerate decryption. GuaWord tests about a trillion keys to guarantee decryption of any password in any language, a process that takes about a day when using GPU acceleration. Fortunately, the download includes a password-protected Word document for demonstration. The program's "interface" is a DOS window describing the file commands. We opened the Command Prompt, typed in the directory and options, and GuaWord opened the test file. That's all there is to it.
GuaWord v1.7's freeware demo version is fully functional but has a fixed password limitation. We tested it in both Windows 7 and Vista. Several licensing options mean you don't have to buy more than you need.