BSOD at startup or password entry

Hi all,

I am experiencing an intermittent BSOD that seems to happen either on waking the computer from standby or at startup, although I have also had it happen once on switching wireless internet from one port to another.

Initially it was just on submitting a password when waking from standby, now it is on all starts unless in safe mode. Norton scans as clear.

Details:
Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7601.2.1.0.768.3
Locale ID: 2057
Additional information about the problem:
BCCode: a
BCP1: 0000000000000000
BCP2: 0000000000000002
BCP3: 0000000000000001
BCP4: FFFFF80002ED7C3F
OS Version: 6_1_7601
Service Pack: 1_0
Product: 768_1
Files that help describe the problem:
C:\Windows\Minidump\071514-29686-01.dmp
C:\Users\Dave\AppData\Local\Temp\WER-50544-0.sysdata.xml

I have attached the SF diagnostic files.

Many thanks!

Attachment 325652

Some additional information: have managed to get to windows out of safe mode and run dm log collector and re-run SF.

The error was IRQL not less than equal (same information as above)

I am a newbie and unskilled so any help very appreciated!

Attachment 325658

Attachment 325659

Update:

I ran WhoCrashed after reading similar issues in other threads, and looks like it's a Symantec driver causing the problem

I will let you know if updating/changing software resolves this but it seems likely it will

Attachment 325663