How can I fix my Advent 7109 laptop?

My Advent 7109 laptop with pre-installed Windows XP Media Centre has completely messed up after I downloaded Windows Service Pack 3,(Recommended by Windows updater).It failed to install twice so I cancelled the installation.When I turned off my laptop after 2 hours of web browsing,my laptop started to auto uninstall my pre-installed service pack 2.Which left me unable to re-boot the pc,(tried everything).So I got my friend to completely wipe the laptop and install his XP home Edition.But I`m having problems,it seems I still having driver and codec issues,and my WLAN is non responsive(not detecting connection.I`m here on my new laptop,but still want to save the old.Can you help me please?