Hi everybody, Im new to your forum and not to up on computers.I was looking for a cure to the windows defender (application failed to initialise 0x800106ba)when i found your forum and read a few stories of the same tale of woe.I have windows vista home premium 2007 edition 32bit.I have checked my event log(problems/reports) and found that defender packed up at the same time bt changed my security from norton to mc affe.Wether these events are involved with each other i dont know.but in a round about way the events lead me to the following.Click on start, type in search box (security centre) click open.Click on windows defender and turn it on.I think with the mcaffe security having its own anti virus programme already it turns windows off. When i downloaded the mcaffe security it had its own norton security uninstall programme built in so no security loss over the internet was achieved while the install/uninstall process took place.Could it be so? Anyway hope this info may help some of you.Be lucky stevieg.