Being very security conscious I have installed on my PC Comodo Firewall Pro, Comodo CAVS AntiVirus, Comodo BoClean and Spyware Blaster installed as real time security. I also have installed AVG AntiSpywareFree Edition, AVG AntiRootkit Free, SpyBot S&D, AdAware 2007 and SuperAntispyware which I use on a sort of rota basis manually, approx 3 - 4 times a week. My question is this. All of the above if/when they detect something either quarantine/delete it without having to reboot my PC except for SuperAntiSpyware which always says it has to reboot my PC in order to get rid of infection ( almost always tracking cookies as my PC is pretty well cared for security wise) Why does this one program need to shut down and reboot my machine to do what the others can do without rebooting?.

It's a feature included in the program by the developer of SAS. An explanation is given in here > Superantispyware Suggests PC Restart .

Certain malware can be stubborn to remove because it's "active' or "in use by other programs". When a reboot occurs, the malware is not yet loaded into the system making easier to remove them. It's similar to when it is suggested to run scans with any AV/AS programs in Safe Mode. In Safe Mode, fewer programs & drivers are loaded making malware removal that much more effective.

Thank you for your reply and the link Hillbillygreek.