Are these the BSoD you're getting after enabling verifier?
Doesn't look like verifier is enabled yet, please enable it.
BugCheck 50 = PAGE_FAULT_IN_NONPAGED_AREA (50) = Usual causes:
Defective hardware (particularly memory - but not just RAM), Faulty system
service, Antivirus, Device driver
, NTFS corruption, BIOS. BSOD Index
BugCheck 3B = SYSTEM_SERVICE_EXCEPTION (3b) = Usual causes:
System service, Device driver, graphics driver, memory. BSOD Index Problematic software:
Start Menu\Programs\AVG Public:Start Menu\Programs\AVG Public
Please uninstall AVG Antivirus while we are troubleshooting with your comp.
Download and install MSE and run a full scan once updated. Microsoft Security Essentials - Free Antivirus for Windows
*Run the system file checker for repairing any damaged files within windows: SFC /SCANNOW Command - System File Checker
*To make sure your hard drive is good, run: Disk Check
*Run the short and long tests with SeaTools: SeaTools for Windows SeaTools for DOS
* Run Memory test for 8 passes preferably overnight. RAM - Test with Memtest86+
Post back results