All your minidumps crash at avg7rsxp.sys. This is your AVG Resident Anti-Virus Shield. It seems that you are running more than one antivirus product as your minidumps also reference naiavf5x.sys. This is part of the McAfee antivirus programme. This may be causing a conflict. It isn`t a good idea to have more than one antivirus active on your system.
1 of your minidumps also references Vax347b.sys. This is the Alcohol120% driver. It is known to cause problems on some systems/configurations.
I suggest uninstalling one of your antivirus programmes, preferably McAfee and see if your crashes disappear.