Microsoft Security Essentials - Now is a good time for a FULL SCAN of hard drive
Using the UPDATE NOW button for MSE all home users should ensure they are up-to-date with the latest virus definitions. On July 15th, Microsoft enhanced their MSE scanning engine and usually this will improve capabilities to better detect or clean malware. While I did a quick scan the day I installed it, it's even better to start a FULL SCAN of your PC and let it run on it's own a few hours (takes about 2 hours on my home PC). While my system was clean, it's a best practice to periodically scan the entire hard drive to ensure it's malware-free.
HOW TO PERFORM FULL SCAN
1. Launch MSE
2. Under HOME TAB, select FULL SCAN
3. Let it start and periodically check as it could run for several hours
Microsoft Security Essentials - New 1.1.6004 Engine Available
http://msmvps.com/blogs/harrywaldron/archive/2010/07/16/microsoft-security-essentials-new-1-1-6004-engine-available.aspx