Spywareblaster 4

Having downloaded this version and followed the instructions on how to delete the older version I found it didn't work. Upon some detective work I found that nothing was in the Registry have tried downloading from different sites to see if it made any difference, but no it didn't, I have tried turning off all my protection, even uninstalling it, all to no avail. The funny thing is it worked on my laptop, now all three of my computers are running the same firewall,Antivirus, Spybot, the only difference is the laptop is running on a HP Windows XP, and the other two are on Windows XP, and Windows XP Professional. Anybody any ideas