Windows 7: Computer Crash

Hello All,
In the last month Win 7 32x, has crashes a few times.
It does no thappen a back to back. I get a blue screen
telling me something I cant read it it goes off to fast.
Could someone tell me how I can find out what is causing
the crash.

Thanks
RalphG.

PS this is the report i have on the crash


Crash Time : 8/7/2011 4:58:07 PM
Bug Check String : IRQL_NOT_LESS_OR_EQUAL
Bug Check Code : 0x0000000a
Parameter 1 : 0xc4c5d000
Parameter 2 : 0x00000002
Parameter 3 : 0x00000000
Parameter 4 : 0x82a707e3
Caused By Driver : ntkrnlpa.exe
Caused By Address : ntkrnlpa.exe+415cb
File Description : NT Kernel & System
Product Name : Microsoft® Windows® Operating System
Company : Microsoft Corporation
File Version : 6.1.7601.17592 (win7sp1_gdr.110408-1631)
Processor : 32-bit
Crash Address : ntkrnlpa.exe+415cb
Stack Address 1 : ntkrnlpa.exe+397e3
Stack Address 2 : pssdklbf.sys+391d
Stack Address 3 : pssdklbf.sys+20f8
Computer Name :
Full Path : C:\Windows\Minidump\080711-37939-01.dmp
Processors Count : 2
Major Version : 15
Minor Version : 7601
Dump File Size : 148,112
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