What is it?

GIANTAntiSpywareMain.exe is microsofts?anti spyware application

What does it do?

Microsoft Windows AntiSpyware (Beta) is a security technology that helps protect Windows users from spyware and other potentially unwanted software

More info:

[url=http://www.microsoft.com/athome/security/spyware/software/about.mspx]microsoft.com[/url]