Windows 7 BlueScreen BCCode d1

[govols]

Started getting Blue Screens about 2 months ago. No happening several times a day. Here are two recent error codes. The minidump files are attached. Any help to find the problem and resolve very much appreciated.

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033

Additional information about the problem:
BCCode: d1
BCP1: F8E8340B
BCP2: 00000002
BCP3: 00000001
BCP4: 8E32223A
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1

Files that help describe the problem:
C:\Windows\Minidump\032110-21668-01.dmp
C:\Windows\Temp\WER-34959-0.sysdata.xml

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033

Additional information about the problem:
BCCode: d1
BCP1: 0001A691
BCP2: 00000002
BCP3: 00000001
BCP4: 8E4AB23A
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1