Gave Microsoft Security Essentials a try, but I decided to go back to avast!.
avast! 5 is almost finished, the final release is targeted at the release of Windows 7 on October 22, so I installed Beta v5.0.167 on my laptop.
Surprisingly it feels lighter than MSE, which is the main reason I gave MSE a trial run in the first place. avast! 5 comes with a new user interface, much nicer than the Winamp skin look in version 4. Scanning of Gmail accounts is now possible with the program handling the secure sign-on to Google’s servers. You have to revert to 110 for POP and 25 for SMTP in Thunderbird as the informative popups from avast! ask you to do.
My favorite change is the female voice that quietly informs me in the morning that the virus definitions have been updated, less authoritative than the old male voice bringing you to attention.
I wanna devise a virus to bring dire straits to your environment
Crush your corporations with a mild touch
Trash your whole computer system and revert you to papyrus