Be a MSP with thousands or tens of thousands of different configurations, all the different antivirus software you can think of, and 20+ years of doing it and you'll see anti-virus break everything you can think of.
AV prevents windows from shutting down.
AV prevents windows from booting up.
AV prevents windows upgrades.
AV prevents windows updates.
AV causes blue screens.
AV quarantines critical windows system files.
AV blocks network resources unexpectedly.
AV cripples network performance.
AV breaks hardware drivers.
AV causes programs to unexpectedly close or crash.
I'd suggest you don't know what experience I have.
I've certainly had problems with anti-virus programs, but no more than I have had with any program, operating system, driver or hardware problem really. Mostly they behave, sometimes they misbehave.
I've rarely seen anti-virus causing shutdown problems. Boot problems have almost always been faulty storage devices or operating system corruption. I've fixed more faulty WU instances that are broken because of Microsoft (recent Win7 authcab problem, IE cumulative years ago, etc). than because of anti-virus. The programs that I have come across that are crashing are rarely solved by removing anti-virus software.
If anti-virus was as widely and horrendously crap as some people keep repeating then I'd know about it because I'd be saying the same thing.
Are you saying av isn't widely crap? Because as a senior sysadmin I agree with gp very much. I don't understand why you are defending av at all honestly. It is one of the crappiest software industries in existence!
Be a MSP with thousands or tens of thousands of different configurations, all the different antivirus software you can think of, and 20+ years of doing it and you'll see anti-virus break everything you can think of.
AV prevents windows from shutting down. AV prevents windows from booting up. AV prevents windows upgrades. AV prevents windows updates. AV causes blue screens. AV quarantines critical windows system files. AV blocks network resources unexpectedly. AV cripples network performance. AV breaks hardware drivers. AV causes programs to unexpectedly close or crash.
Are just a common list I have to deal with.