why does running 2 anti-virus programs cause conflict?

altitude · 10-30-2009, 10:07 PM

I know that having 2 anti-virus programs running in real-time mode will cause conflict but can anyone explains the exact reason why doing so will cause conflict?

Thanks

**Glaswegian** · 10-31-2009, 08:33 AM

Hi

Perhaps this is not 'exact' but it should give you an idea...

The real time monitors check files - especially files that change - and this can be many, many files depending on what your system is doing, applications open etc. So, a file changes. AV1 notices the file has changed and checks the file. AV2 then notices that the file has changed because AV1 has had a peek at it. So AV2 has a peek as well. Now, AV1 sees that the file has changed and it wants another peek. AV2 then sees the file has changed again so it needs another peek...and so on.

You could then have both AVs trying to peek at the same files at the same time, thus causing system slow downs, BSODs etc, etc

As I said, not exact but hopefully it helps to explain what happens.

altitude · 11-01-2009, 10:22 AM

Wow, that's a very nice explanation and very logical too. I see what you mean there pal!

10-30-2009, 10:07 PM	#1 (permalink)
altitude Registered User Join Date: Oct 2009 Posts: 4 OS: Windows XP SP3	why does running 2 anti-virus programs cause conflict? I know that having 2 anti-virus programs running in real-time mode will cause conflict but can anyone explains the exact reason why doing so will cause conflict? Thanks

10-31-2009, 08:33 AM	#2 (permalink)
Glaswegian Moderator/ Rangemaster TSF Academy; Analyst, Security Team; Oor Wullie; TSF Surgeon and Resident Comic Join Date: Sep 2005 Location: Glasgow Posts: 25,512 OS: Win XP Pro SP3 / Win 7 Pro My System Blog Entries: 10	Re: why does running 2 anti-virus programs cause conflict? Hi Perhaps this is not 'exact' but it should give you an idea... The real time monitors check files - especially files that change - and this can be many, many files depending on what your system is doing, applications open etc. So, a file changes. AV1 notices the file has changed and checks the file. AV2 then notices that the file has changed because AV1 has had a peek at it. So AV2 has a peek as well. Now, AV1 sees that the file has changed and it wants another peek. AV2 then sees the file has changed again so it needs another peek...and so on. You could then have both AVs trying to peek at the same files at the same time, thus causing system slow downs, BSODs etc, etc As I said, not exact but hopefully it helps to explain what happens. __________________ Iain - Defender of the Haggis and all things Scottish. I don't help by PM - post in the Forums. PC Safety & Security::PC running a bit slow?::Donate::Photographers Corner

11-01-2009, 10:22 AM	#3 (permalink)
altitude Registered User Join Date: Oct 2009 Posts: 4 OS: Windows XP SP3	Re: why does running 2 anti-virus programs cause conflict? Wow, that's a very nice explanation and very logical too. I see what you mean there pal!