Getting ramdom bsod

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Dump File : 031812-11091-01.dmp
Crash Time : 3/18/2012 1:00:19 PM
Bug Check String : SYSTEM_SERVICE_EXCEPTION
Bug Check Code : 0x0000003b
Parameter 1 : 00000000`c0000005
Parameter 2 : 00000000`00000000
Parameter 3 : fffff880`04897c80
Parameter 4 : 00000000`00000000
Caused By Driver : ntoskrnl.exe
Caused By Address : ntoskrnl.exe+7cd40
File Description : NT Kernel & System
Product Name : Microsoft® Windows® Operating System
Company : Microsoft Corporation
File Version : 6.1.7601.17727 (win7sp1_gdr.111118-2330)
Processor : x64
Crash Address : ntoskrnl.exe+7cd40
Stack Address 1 :
Stack Address 2 :
Stack Address 3 :
Computer Name :
Full Path : C:\Windows\Minidump\031812-11091-01.dmp
Processors Count : 6
Major Version : 15
Minor Version : 7601
Dump File Size : 275,824
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Dump File : 033112-12074-01.dmp
Crash Time : 3/31/2012 11:22:31 AM
Bug Check String : SYSTEM_SERVICE_EXCEPTION
Bug Check Code : 0x0000003b
Parameter 1 : 00000000`c0000005
Parameter 2 : 00000000`00000000
Parameter 3 : fffff880`047a7d30
Parameter 4 : 00000000`00000000
Caused By Driver : ntoskrnl.exe
Caused By Address : ntoskrnl.exe+7cd40
File Description : NT Kernel & System
Product Name : Microsoft® Windows® Operating System
Company : Microsoft Corporation
File Version : 6.1.7601.17727 (win7sp1_gdr.111118-2330)
Processor : x64
Crash Address : ntoskrnl.exe+7cd40
Stack Address 1 :
Stack Address 2 :
Stack Address 3 :
Computer Name :
Full Path : C:\Windows\Minidump\033112-12074-01.dmp
Processors Count : 6
Major Version : 15
Minor Version : 7601
Dump File Size : 275,824
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Dump File : 033112-11887-01.dmp
Crash Time : 3/31/2012 10:24:00 AM
Bug Check String : SYSTEM_SERVICE_EXCEPTION
Bug Check Code : 0x0000003b
Parameter 1 : 00000000`c0000094
Parameter 2 : fffff880`05363aad
Parameter 3 : fffff880`046c7c60
Parameter 4 : 00000000`00000000
Caused By Driver : sptd.sys
Caused By Address : sptd.sys+a86e2
File Description :
Product Name :
Company :
File Version :
Processor : x64
Crash Address : ntoskrnl.exe+7cd40
Stack Address 1 :
Stack Address 2 :
Stack Address 3 :
Computer Name :
Full Path : C:\Windows\Minidump\033112-11887-01.dmp
Processors Count : 6
Major Version : 15
Minor Version : 7601
Dump File Size : 275,824
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