Recently my computer was infected

This was the first major infection that got by Microsoft Security Essentials which I had used for about 2 years after my paid antivirus had expired. Security Essentials seemed to be working since I never had any serous problems, but about 2 weeks ago I received a message that my computer was infected by "Trojan

OS/Alureon.A" and Microsoft Security Essentials could not remove this infection and I should go to the Security Essentials website and create a boot repair disc. I created the repair disc, but it didn't work, then I searched for a solution online and tried several of the solutions I found but none worked. I tried Emsisoft Anti-Malware which found several other problems but it couldn't remove the virus imbedded in my boot files. Finale I removed Microsoft Security Essentials and installed AVAST. AVAST found the infection told me I needed to run a boot-time scan, which I did. The AVAST boot scan removed the virus along with several infected programs. My computer is clean and all I had to do was reinstall the programs that the virus had damaged and no-longer worked, if you still need that program. This is a good time to clean out stuff you no-longer use!
Thank You AVAST and Techsupport