If so, it is likely that some trial security software was pre-installed at the factory. I had a similar problem with this new laptop I have. It came pre-installed with Norton Internet Security, despite me specifically ordering without, and when I attempted to install ZoneAlarm firewall with anti-virus and anti-spyware, Windows told me there was a conflict. I had to uninstall Norton first.

PC Cillin is from Trend Micro, so may be your Vista > Control Panel > Programs & Features listing has this under Trend Micro. If so, try uninstalling that. Different guidance here for Uninstalling Trend Micro products.

Many of these security software utilities now need specific uninstall procedures, so although you say you have uninstalled CA Security, there may be remnants left behind. It's a security measure to help prevent malware from attempting the same uninstall.

If you find and successfully uninstall Trend Micro, reboot (restart) the system, then try and re-install CA Security.

You mentioned a malware problem. What problem is that?

Mark