Weird. Something is messed with your machine, so a Safe Boot (restarting with the shift key pressed after the startup tone) is at least needed. Restart normally once Safe boot is finished.

Move (or delete) all the old install.dmg's on your desktop, and download a fresh one from Lime Wire » Official Website & Free Download, BitTorrent «

Try again. if Word still tries to take control, find and open the Installer Utility (in your Utilities folder). Once open, drag the LW icon from the dmg to the Installer icon in the dock. That should force the installer to run the install program instead of Word.