"Multi-layering" security itself a hazard?

[6MONTAGE]

On the one hand, articles I've read recommend using several programs, antivirus and antispyware and antimalware, for security.

On the other hand, I've been told by a techie that using more than one resident anti-spyware program can itself cause instability in the operating system and applications.

Which is correct?

Any guru who wishes to share what they do?

 

[Yeti]

Well, I could see there being conflicts if two real-time protection programs are running. Other than that the only thing I know of is that one anti-spyware program will quarantine a file and another program will scan that quarantine and pick it out which can cause problems. Can anyone else think of any more reasons?

 

[Cromewell]

well in the case of antispyware utilities, if you use something that blocks spyware from installing it could cause the 2nd install blocker to see it as a spyware program blocking install of a real program and block it there by letting it though. This is probably rare and may never happen but running 2 live protection things is almost always a bad idea. Multiple scanners is ok, just not multiple 'live protection' type programs

 

[Sebouh]

well that's true, i use one real time protection for spyware and 3 (including itself) for just scanning. For Firewall and AntiVirus protection, i use norton Internet Security.