Ok, here's what I've tried but no luck:
2) sfc /scannow
3) Run ZA clean tool
4) Search and remove everything in files, folders and registry that contains "zonealarm" or "checkpoint"
5) Run Ccleaner, MBAM, superantispyware, emergency kit & hitman pro
Then tried reinstall and no joy - it does the same as before in that it seems to get to the end of the install but then just stops before I get any set up options pop up. I did notice that after the install windows security center was reporting that ZA firewall and AV was up to date and working. Whenever I try to manually start ZA I get the pop up asking me if I want to continue evaluating or enter a license code and the icon appears in system tray saying "ui is initialising", but as soon as I make a selection in the pop up nothing happens except the icon disappears if I put the cursor over it.
Anyway got any final suggestions before I give up on ZA after many years of happy use and go over to a competitor? As the issue only affects ZA and everything else is fine with no infectiosn found I'm loath to reinstall the OS just for ZA.