BSOD, Seems Random, Tho could be Gfx related

Norton is a very frequent cause of BSOD's.

Replace with Microsoft Security Essentials & the Free version of Malwarebytes, update and make full scans separately:

Uninstallers (removal tools) for common antivirus software - ESET Knowledgebase

Microsoft Security Essentials - Microsoft Windows

Malwarebytes Free

• Do not start the trial version of MalwareBytes
  

You may also take a look at:

Good & Free System Security Combination

Use the System File Checker tool and Run Disk Check:

Repair Windows 7 System Files with System File Checker

Run Disk Check in Windows 7 for Bad Sectors & Errors

Make scans with -

TDSSKiller Rootkit Removal Utility Free Download | Kaspersky Lab US

Online Virus Scanner Eset

Reduce items at start up:

Performing a Clean Startup in Windows 7

Add, or Remove Startup Programs in Windows 7

Your Antivirus software is basically whats just needed there.

Follow this -

writhziden said:

If you have an SSD, make sure the following are up to date:

• SSD firmware
• BIOS Version
• Chipset Drivers
• Hard disk controller drivers/SATA drivers
• If you have a Marvell IDE ATA/ATAPI device, make sure the drivers are up to date from the Intel site or Marvell site and not from your motherboard/vendor support site.

Drivers

AppleCharger.sys Thu Oct 25 06:51:02 2012
GIGABYTE On/Off Charge driver. Tends to cause BSOD's please remove

AODDriver2.sys Tue Mar 6 15:55:00 2012
AMD Overdrive; also in EasyTune6 for Gigabyte motherboard [br] Known BSOD issues in Win7 Please remove this as well.

   Note

Download and install Revo Uninstaller free from here:

Download Revo Uninstaller Freeware

Opt for "Advanced Mode" and uninstall the software (also delete the leftover registry entries).

xusb21.sys Fri Aug 14 04:10:17 2009
Outdated, please update to its latest version available. - Driver Reference Table - xusb21.sys

As for your GFX card, have you tried another card on your system, tried the card on another system?
Does that make a difference?

Test your Hardware for Stability and Heat Problems with Prime95:

Stress Test With Prime95

How to Stress Test a Video Card with Furmark:

Video Card - Stress Test with Furmark

Test your CPU Stability with IntelBurnTest:

CPU - Stress Test Using IntelBurnTest

When Furmark fails - there are still several possibilities.

1. The most common ones -
2. - Faulty Graphics Card
3. - Underpowered/Faulty PSU (what is your PSU? Brand? Model?)
4. - Faulty RAM (this is unlikely as you say the Prime95 Blend test and Memtest didn't show errors?)
5. - Faulty Motherboard (unlikely - as it's been replaced)
6. - Faulty CPU (very unlikely - anyway, Prime95 passed)

Monitor hardware temperature with system monitoring software like Speccy or HWMonitor:

Piriform - Speccy

CPUID - HWMonitor

BUGCHECK SUMMARY:

Code:

Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sun Jul 28 23:21:32.595 2013 (UTC + 6:00)
System Uptime: 0 days 12:36:31.791
BugCheck 3B, {c0000005, fffff96000164e32, fffff88007de10c0, 0}
Probably caused by : win32k.sys ( win32k!TimersProc+126 )
BUGCHECK_STR:  0x3B
PROCESS_NAME:  csrss.exe
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sat Jul 27 19:24:56.176 2013 (UTC + 6:00)
System Uptime: 0 days 5:32:31.064
BugCheck A, {fffffa7fffffe7e0, 2, 1, fffff80002c3bac1}
Probably caused by : memory_corruption ( nt!MmZeroPageThread+3c4 )
BUGCHECK_STR:  0xA
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Fri Jul 26 23:28:31.786 2013 (UTC + 6:00)
System Uptime: 0 days 3:05:57.675
BugCheck 1000007E, {ffffffffc0000005, fffff80002c8bcb4, fffff880091baa58, fffff880091ba2b0}
Probably caused by : dxgmms1.sys ( dxgmms1!VidSchiWorkerThread+4b )
BUGCHECK_STR:  0x7E
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Fri Jul 26 20:21:25.005 2013 (UTC + 6:00)
System Uptime: 0 days 6:26:19.253
BugCheck A, {8, 2, 1, fffff80002c9f502}
Probably caused by : ntkrnlmp.exe ( nt!KiTimerExpiration+f2 )
BUGCHECK_STR:  0xA
PROCESS_NAME:  System
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sun Jul 21 20:46:43.431 2013 (UTC + 6:00)
System Uptime: 0 days 6:43:07.320
BugCheck 3B, {c0000005, fffff80002fc47b2, fffff88007a5e1d0, 0}
Probably caused by : ntkrnlmp.exe ( nt!NtWaitForSingleObject+b2 )
BUGCHECK_STR:  0x3B
PROCESS_NAME:  Wow-64.exe
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sun Jul 21 04:33:49.524 2013 (UTC + 6:00)
System Uptime: 0 days 12:51:11.773
BugCheck 3B, {c0000005, fffff80002db3147, fffff8800c90be70, 0}
Probably caused by : ntkrnlmp.exe ( nt!ExAllocatePoolWithTag+537 )
BUGCHECK_STR:  0x3B
PROCESS_NAME:  svchost.exe
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
Debug session time: Sat Jul 20 15:41:59.686 2013 (UTC + 6:00)
System Uptime: 0 days 0:59:41.935
BugCheck 7F, {8, 80050031, 6f8, fffff80002c75041}
Probably caused by : ntkrnlmp.exe ( nt!KiDoubleFaultAbort+b2 )
BUGCHECK_STR:  0x7f_8
PROCESS_NAME:  csrss.exe
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``

Good luck.

Thanks for the update.
Post should you have further issues.