irql_not_less_or_equal BCC code a

I've been getting the blue screen of death with a message irql_not_less_or_equal

Other info

BCC code a
BCP1 C0343000
BCP2 00000000
BCP3 00000000
BCP4 93CD9FD1

0S version 6-0-6002 service pack 2
Product 768-1

I've uploaded DMP files from yesterday & today - I hope you can help

Welcome
Hopefully, easy to resolve. It looks like its your anti virus, Symantec. Usiing the Symantec uninstall tool, uninstall and use Microsoft Security Essentials. You can also use the free Malwarebytes to make once a week scan. I have seen BSODs from all antivirus with the exception of Secrity Essentials.
Symevent.sys file descriptionProductname: SYMEVENT Description: Symantec Event Library Company: Symantec Corporation