BSOD at odd times, also freezes that require forced shutdown

Is the firmware for your SSD up-to-date?

Check for one and see if the stability returns.

Security App
Crashes indicate Norton being a possible cause. Remove Norton and replace with Microsoft Security Essentials to see if it provides more stability. Uninstallers (removal tools) for common antivirus software

Microsoft Security Essentials and Malwarebytes are recommended from a strict BSOD perspective. They do not cause blue screens on the system as other AV products do.

Microsoft Security Essentials for Windows
MalwareBytes Free

   Information

• Do not start the free trial of MalwareBytes, unselect that option when prompted.
  
  
• Update and make full scans with both separately.

Virus check
Scan your system with the following:

Kaspersky TDSSKiller - TDSSKiller Rootkit Removal Utility Free Download | Kaspersky Lab US

ESET online scanner - Online Virus Scanner Eset

Windows Defender Offline (optional)/in case above two show infection) - Run Windows Defender Offline

Hard Drive/Storage
Post disk summary using CrystalDiskInfo software - CrystalDiskInfo

For how to upload a screenshot or file, read here

Make a Hard Drive test from the mfg website: Hard Drive Diagnostic Procedure

For errors on your Hard drive(s): Disk Check

Start up
Keep less stuff at the start-up. Only anti-virus, this helps avoid driver conflicts and improves time to log in to windows.

Performing a Clean Startup
Startup Programs - Change

SFC /scannow

1. Click Start
2. In the search box, type Command Prompt
3. In the list that appears, right-click on cmd.exe and choose Run as administrator
4. In the command window that opens, type

Code:

sfc /scannow

5. Hit enter
System File Checker

System Temperature

Ensure that there are no heat issues, For monitoring heat of the system use Piriform - Speccy or Hardware Monitor

Memtest86+
Run Memtest86+ for at least 8-10 passes. It may take up to 20 passes to find problems. Make sure to run it once after the system has been on for a few hours and is warm, and then also run it again when the system has been off for a few hours and is cold.
How to test and diagnose RAM issues with Memtest86+

   Note

Pay close attention to part 3 of the tutorial in order to rule the faulty RAM stick out.

   Tip

Do this test overnight.

BSOD BUGCHECK SUMMARY

Code:

Debug session time: Sat Jul  6 23:25:59.088 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 0:27:00.994
*** WARNING: Unable to verify timestamp for SRTSP64.SYS
*** ERROR: Module load completed but symbols could not be loaded for SRTSP64.SYS
Probably caused by : SRTSP64.SYS ( SRTSP64+40ce1 )
BugCheck 19, {21, fffff8a00a99f000, 1010, 10000001010}
BugCheck Info: BAD_POOL_HEADER (19)
Bugcheck code 00000019
Arguments: 
Arg1: 0000000000000021, the data following the pool block being freed is corrupt.  Typically this means the consumer (call stack ) has overrun the block.
Arg2: fffff8a00a99f000, The pool pointer being freed.
Arg3: 0000000000001010, The number of bytes allocated for the pool block.
Arg4: 0000010000001010, The corrupted value found following the pool block.
BUGCHECK_STR:  0x19_21
PROCESS_NAME:  System
FAILURE_BUCKET_ID:  X64_0x19_21_SRTSP64+40ce1
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Debug session time: Sat Jul  6 22:58:00.394 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 0:06:06.299
*** WARNING: Unable to verify timestamp for SRTSP64.SYS
*** ERROR: Module load completed but symbols could not be loaded for SRTSP64.SYS
Probably caused by : Pool_Corruption ( nt!ExDeferredFreePool+a53 )
BugCheck 19, {3, fffffa800aeca7e0, fffffa800aeca7e0, fffffb800aeca7e0}
BugCheck Info: BAD_POOL_HEADER (19)
Bugcheck code 00000019
Arguments: 
Arg1: 0000000000000003, the pool freelist is corrupt.
Arg2: fffffa800aeca7e0, the pool entry being checked.
Arg3: fffffa800aeca7e0, the read back flink freelist value (should be the same as 2).
Arg4: fffffb800aeca7e0, the read back blink freelist value (should be the same as 2).
BUGCHECK_STR:  0x19_3
PROCESS_NAME:  svchost.exe
FAILURE_BUCKET_ID:  X64_0x19_3_nt!ExDeferredFreePool+a53
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Debug session time: Sat Jul  6 06:45:52.554 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 0:06:46.865
Probably caused by : Ntfs.sys ( Ntfs!NtfsFcbTableCompare+3 )
BugCheck 24, {1904fb, fffff88002c807d8, fffff88002c80030, fffff88001904a53}
BugCheck Info: NTFS_FILE_SYSTEM (24)
Bugcheck code 00000024
Arguments: 
Arg1: 00000000001904fb
Arg2: fffff88002c807d8
Arg3: fffff88002c80030
Arg4: fffff88001904a53
PROCESS_NAME:  svchost.exe
BUGCHECK_STR:  0x24
DEFAULT_BUCKET_ID:  WIN7_DRIVER_FAULT
FAILURE_BUCKET_ID:  X64_0x24_Ntfs!NtfsFcbTableCompare+3
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Debug session time: Sat Jul  6 06:38:07.586 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 2:38:31.881
*** WARNING: Unable to verify timestamp for iaStor.sys
*** ERROR: Module load completed but symbols could not be loaded for iaStor.sys
Probably caused by : iaStor.sys ( iaStor+7626c )
BugCheck 7F, {8, 80050033, 406f8, fffff880012cc26c}
BugCheck Info: UNEXPECTED_KERNEL_MODE_TRAP (7f)
Bugcheck code 0000007F
Arguments: 
Arg1: 0000000000000008, EXCEPTION_DOUBLE_FAULT
Arg2: 0000000080050033
Arg3: 00000000000406f8
Arg4: fffff880012cc26c
BUGCHECK_STR:  0x7f_8
PROCESS_NAME:  System
FAILURE_BUCKET_ID:  X64_0x7f_8_iaStor+7626c
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Debug session time: Sat Jul  6 03:38:50.088 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 0:04:27.009
Probably caused by : CI.dll ( CI!I_ReloadCatalogs+14a )
BugCheck 50, {fffffb800b4d17d0, 1, fffff80002ec7aee, 7}
BugCheck Info: PAGE_FAULT_IN_NONPAGED_AREA (50)
Bugcheck code 00000050
Arguments: 
Arg1: fffffb800b4d17d0, memory referenced.
Arg2: 0000000000000001, value 0 = read operation, 1 = write operation.
Arg3: fffff80002ec7aee, If non-zero, the instruction address which referenced the bad memory
	address.
Arg4: 0000000000000007, (reserved)
BUGCHECK_STR:  0x50
DEFAULT_BUCKET_ID:  WIN7_DRIVER_FAULT
PROCESS_NAME:  System
FAILURE_BUCKET_ID:  X64_0x50_CI!I_ReloadCatalogs+14a
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``
Debug session time: Fri Jul  5 11:20:40.147 2013 (UTC + 6:00)
Built by: 7601.18113.amd64fre.win7sp1_gdr.130318-1533
System Uptime: 0 days 7:21:18.053
*** WARNING: Unable to verify timestamp for iaStor.sys
*** ERROR: Module load completed but symbols could not be loaded for iaStor.sys
Probably caused by : iaStor.sys ( iaStor+7626c )
BugCheck 7F, {8, 80050033, 406f8, fffff8800128f26c}
BugCheck Info: UNEXPECTED_KERNEL_MODE_TRAP (7f)
Bugcheck code 0000007F
Arguments: 
Arg1: 0000000000000008, EXCEPTION_DOUBLE_FAULT
Arg2: 0000000080050033
Arg3: 00000000000406f8
Arg4: fffff8800128f26c
BUGCHECK_STR:  0x7f_8
PROCESS_NAME:  System
FAILURE_BUCKET_ID:  X64_0x7f_8_iaStor+7626c
MaxSpeed:     3100
CurrentSpeed: 3090
BiosVersion = P03-A3
BiosReleaseDate = 04/18/2012
SystemManufacturer = Gateway
SystemProductName = DX4860
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨``