You may consider using OpenOffice Suite, an MS Compatible office suite, it is provided free of charge and it is very powerful. You can download the software from OpenOffice.org web site.

this will allow you to fill out the forms without the use of having MS Word installed in your computer, however Tab-fillable forms feature is not supported.

Another option is to use Microsoft Word Viewer, this utility allows you to view and print Word documents, however it is limited to only viewing and printing documents, you may not edit them, the utility may be downloaded here.