While Avira currently holds the number two ranking in terms of usage amongst antivirus manufacturers worldwide, its latest slipup will likely put a dent in its reputation. The problem with the latest service pack can be pinpointed to ProActiv, a program that monitors for any suspicious events that could lead to infection or attack. Users who applied the updates noticed that ProActiv was preventing their systems from booting, as critical Windows files could not run. Others also reported that ProActiv was blocking all .exe, or executable files, in Windows, making it impossible to launch appl...