Originally, Windows Defender was a simple anti-spyware program offered by Microsoft. It was not a full anti-malware suite. I also think it was offered as part of the installed programs with Windows 7. In 2009 (if I remember correctly) Microsoft offered a full anti-malware suite and called it Microsoft Security Essentials and pretty much phased out Windows Defender.
Fast forward and Microsoft offered yet another product called Windows Defender Offline which is a free standalone, bootable malware and virus remover that performs an offline scan of an infected PC to remove viruses, rootkits and other advanced malware.
Then when Windows 8 was released, Microsoft once again decided to confuse people by calling the provided anti-malware suite Windows Defender even though, for all intents and purposes, it is identical to Microsoft Security Essentials.
Thanks for the gen, I am a little less confused now. I run XP, 7 and 8 with the Microsoft product on 7 and 8 and have had no problems so far. A quick scan is fast but a full scan takes ages.
My Computer
Computer type
PC/Desktop
OS
w7 ult 64 and w7 hp 64 X 2 mint 64 8.1 64 10wtp 64