hello. your best way to obtain a copy of Microsof Word is to go to eBay and search for one of the older version like MS Word 97 or any other made afterwards. The 2007 version of MS Word is going to be expensive no matter what you do. Make sure the seller is providing you wish a disc free of scratches and that it has a product software key included. Without a key, you can't activate the software at all. My suggestion would be Microsoft Word 2000 as the choice.
You can check out www.download.com and see if there are any free to use word processors there to download too. However, don't count on it. Most of them will be shareware that you can only use for like 30 days unless you pay for the full rights to it. However, you just might find a word processor there you can download for free and use for your files.
There's always torrent sites to download copies of MS Word for free, but that is illegal and I can't go into that answer here in this format.
Also, if you can get to one, there is always a public library. That's assuming it has a decent, modern computer section to use. Perhaps you have a friend or relative you can visit to use their computer for the time being? Maybe your relatives or friends have an old version of MS Word sitting around that they no longer use because they are using the more modern version?
As some of the other answers have said, there are free off-brand versions of word processors out there for those unable to afford a commerical version. I suggest this link and version by Open Office which is free and used widely http://download.openoffice.org/index.html
You said you had trouble with it beforehand, and I cannot account for that, seeing how I've never used the software myself. Just a suggestion in case you have to use it again. I state this option simply for future readers of this topic.
Seriously though, your best bet is get your hands on a copy of the older versions either through eBay or a small time mom-and-pop computer software merchant living near you. Just so you know, the major retailers like Best Buy, Wal-Mart, Circuit City, etc. will not be selling old versions of MS Word. They only sell the most up-to-date version on their shelves. You can also try out Amazon.com and see what they have for MS Word products.