Is this a fresh install, or has it been working fine and is now all of a sudden crashing? When is it crashing (e.g. when you open a document, when you try to change pages, ...)?
I would first try to repair the installation - you can find this option under the help menu. If that does not work, uninstall, download again and re-install Reader. You may also want to try the Reader CLeaner tool after you uninstall: http://labs.adobe.com/downloads/acrobatcleaner.html - this will remove any trace of Reader on your system.
Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...