Help fix BSOD with ntoskrnl.exe

First time poster. Thanks in advance for any help.

I just got a BSOD and ran WhoCrashed to see what's going on and it turns out this is the third BSOD in three months and somehow I didn't notice the other ones happen.

On Tue 1/6/2015 4:01:18 AM GMT your computer crashed
On Tue 2/10/2015 10:50:17 AM GMT your computer crashed
On Tue 3/10/2015 10:40:17 PM GMT your computer crashed

It seems really odd that all three times were almost the same date and time of each month. And I use this computer a lot so there's no chance I was only on the computer those particular days.

I haven't been able to copy or upload the dump files with access denied errors. I used the Take Ownership command on right click and it said I was successfully given permissions but I still can't do anything with them.

Here's the WhoCrashed report:

System Information (local)

computer name: E530-PC
windows version: Windows 7 Service Pack 1, 6.1, build: 7601
windows dir: C:\Windows
Hardware: 3259AD9, LENOVO
CPU: GenuineIntel Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz Intel586, level: 6
4 logical processors, active mask: 15
RAM: 6016606208 total



Crash Dump Analysis

Crash dump directory: C:\Windows\Minidump

Crash dumps are enabled on your computer.

On Tue 3/10/2015 10:40:17 PM GMT your computer crashed
crash dump file: C:\Windows\Minidump\031015-8985-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x74EC0)
Bugcheck code: 0x1A (0x5100, 0xFFFFF6FD40029008, 0x1FF, 0xFFFF000000002028)
Error: MEMORY_MANAGEMENT
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: This indicates that a severe memory management error occurred.
This might be a case of memory corruption. More often memory corruption happens because of software errors in buggy drivers, not because of faulty RAM modules.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.



On Tue 2/10/2015 10:50:17 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\021015-7737-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x76E80)
Bugcheck code: 0x50 (0xFFFFFBFA025381B0, 0x0, 0xFFFFF80002AD1CDC, 0x7)
Error: PAGE_FAULT_IN_NONPAGED_AREA
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: This indicates that invalid system memory has been referenced.
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.



On Tue 1/6/2015 4:01:18 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\010515-6692-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x75BC0)
Bugcheck code: 0xA (0xFFFFF88022F65180, 0x2, 0x0, 0xFFFFF80002A785DF)
Error: IRQL_NOT_LESS_OR_EQUAL
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: This indicates that Microsoft Windows or a kernel-mode driver accessed paged memory at DISPATCH_LEVEL or above.
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.