Q: Mac OS X v10.7 software update quits

Make sure your data is backed up.   10.7.5 is the latest version of 10.7.   If you are attempting to apply security updates, download them directly from:

http://support.apple.com/kb/HT1222

If you need 10.8 or later for something you have to purchase it from the Mac App Store. Use this guide on what else you'll need to know:

https://discussions.apple.com/docs/DOC-3761