Finally managed to install software successfully. This is what I did:
I downloaded and installed the Enterprise Version HP Officejet Enterprise Driver - IT Professional Use Only 2012-10-22 , Version:14.8.0, 39.97M from here http://h10025.www1.hp.com/ewfrf/wc/softwareCategory?os=4132&lc=en&cc=uk&dlc=en&sw_lang=&product=3919449#N222
But this software did not find my printer even though it installed completely.
Then I downloaded HP Officejet Full Feature Software and Driver 2012-10-22 , Version:14.8.0, 301.54M from same page as above.
Opened the downloaded file. It Extracted and this time setup started. BE PATIENT!!! First it automatically uninstalled the corporate software just installed. It rebooted. and then the setup for the Full feature software started and ended successfully. AT LAST!!!
Hope this helps.