STOP 0x00000050: PAGE_FAULT_IN_NONPAGED_AREA
Usual causes: Defective hardware (particularly memory - but not just RAM), Faulty system service, Antivirus, Device driver, NTFS corruption, BIOS
Your latest dump file lists dxgmms1.sys as the probable cause. This is a Windows System file related to graphics and for it to be the cause of your crash is highly unlikely.
You're also getting a lot of different stop errors which may indicate hardware.
Old and incompatible drivers can and do cause issues with Windows 7, often giving false error codes.
As a Priority:
AVG is known to be a cause of BSOD's on Windows 7 systems. Suggest that you uninstall it. Download the correct Link Removed...