[zofo5547]

does RUNNING TWO versions of anti virus at the same effect the preformance of the computer?

[Elvandil]

Yes. It may prevent viruses from being detected. It will have almost no good result. Most install driver-level components that may conflict on boot and while running. Scanning files when opened uses CPU and they would be trying to do that simultaneously which could noticeably slow things. Due to unpredictable interactions, neither could be trusted to do a good job.

[xrztrx]

shouldnt run 2 av at the same time although i use kaspesky av for on demand scanning and nod32 for real time