Manually install Microsoft Security Essential Definition Updates
Microsoft Security Essentials is a free antivirus and antispyware program for windows which provides real-time protection for your home PC that guards against viruses, spyware, and other malicious software.
Once you installed Microsoft Security Essentials (MSE), you would need to update it with latest virus definitions which requires around 40MB download.
If you are facing any problem (like internet problem, updates stops…) while trying to install definition updates for Microsoft Security Essentials Now you can manually download and install latest definition updates from Microsoft.
You don’t have to play with your MSE to update it (as other antivirus program does). All you need to do is just download the latest definition updates (46Mb) and double-click on it (Mpam-fe.exe) to install. Done!.