McAfee v Spywareblaster?
 

I know they don't do the same job but will McAfee's prog. stop me installing other anti- whatsits?
I have just got a new PC (yipee!) and it's arrived preloaded with a trial version of McAfee's Active Scan( I think). Taking Liam's words as gospel I thought I'd also load up both Spywareguard and Spywareblaster, but both refused to install. Both Spybot and Adaware installed ok but not the aforesaid programmes. I managed to do this on my old PC which had Trends, PC-Cillin as my main a/virus programme. Could it be McAfee or something else? Perhaps the internet security settings?