What type of word document should I download (read)

I have a windows XP PC and the word processor isn’t installed and I cannot find the papers and do not have the cash to re-buy the disc or whatever I need to download it.
I need this for my weekly english homework. I downloaded a program called “Tinyword” and when I sent it to my teacher she said she could not open it. The document came out as squares. She’s using a Dell XP PC, too.