Vista intermittant crash

I have Windows Vista Ultimate Service Pack 1. I am seeing a blue screen intermittently. Sometimes the blue screen appears after 15-20 minutes of working on the system, sometimes it just happens when I log in.
There is no definite activity or application after which it happens.
Most of the time I see this STOP 0x0000001A and different numbers in the brackets ( 0x00000030,0x8AA367B0,0xA9CF0000,0xAECC588) .
This seems to refer to a memory problem.


I ran a chkdsk and it didn't specify any problem but a generic statement that hardware problem may be there ,contact the manufacturer.

I have several dumps in my minidumps folder. I have attached some of the recent ones.
If someone can let me know the exact cause of the problem it would be great.

I guess the first step would be to know whether its a hardware problem or a software problem.

I did not do a full analysis. Lets try an easy solution which appears as the potential cause
Make a system restore point.
Uninstall Mcafee with the uninstall tool
Install Microsoft Security Essentials
Remove Daemon or Alchohol 120%
Then test. If another BSOD post it here
if not
Just keep Mcafee away from the computer
How to uninstall or reinstall supported McAfee consumer products using the McAfee Consumer Products Removal tool (MCPR.exe)

and


Please remove any CD virtualization programs such as Daemon Tools and Alcohol 120%. They use a driver, found in your dmp, sptd.sys, that is notorious for causing BSODs. Use this SPTD uninstaller when you're done:
http://www.duplexsecure.com/en/faq