Files ending in .gz are files that have been compressed with gzip, which Word and Windows don't support. Under Windows, PowerArchiver 6.1, 7-zip and Winzip support decompressing gzip - 7-zip is free here: http://www.7-zip.org/
Use that to extract the faa files.
Nonetheless, I wouldn't recommend opening these files with Word, as Word a) loads the whole file into memory which can cause problems with your other running processes and b) Word inserts a lot of hidden stuff when you save it, causing problems downstream. Here are some recommendations for text editors which can open large files under Windows: http://stackoverflow.com/a/159537 (these work because they only load the piece of the file you are currently looking at into memory)