It's not possible to install Word 2000 because the Office package which belongs to it is discontinued. There are newer versions of Office available for installation. The DOC file should be generally compatibility with newer versions of Word. However, if you have problems with formatting, it's because of Word 2000. The new Word should display the file properly if you've saved to DOC format. Any other format will give you layout/formatting issues.
Additionally, if you have the Word package, try installing it on a new PC, but make sure to remove the current version from your computer. If you use Windows Vista or higher, run the installation package as Administrator to prevent any errors related to security and file permissions.