I have encountered some problems with windows defender recently and Windows 8 has run a long time on my pc. Few days ago I've installed Microsoft Security Essentials on my pc and then uninstalled free AVG. then installed another anti-virus program and the whole installation process was very successful. Next day I noticed that Microsoft Security Essentials are working fine, but the newly instaleld Defender was OFF.
does anyone know what could be causing this? maybe i've missed some important steps and hope you can come up a fix for this.
many thanks in advance.