neieus :
Download who crashed and have it read the minidump information provided from the blue screen then post it here. That will give us more of an idea of what's going on. Looking at what you have provided already the ntoskrnl will only crash due to a device driver so with luck that dump data will tell you which driver caused the problem.
Here is what whocrashed told me for the last few dumps, doesn't look like it knows which driver it is. Do you think I can rule out hardware?
On Wed 9/30/2015 10:34:06 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\093015-17687-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x12685A)
Bugcheck code: 0x1000007E (0xFFFFFFFFC0000005, 0xFFFFF8033132E85A, 0xFFFFD000C66B64E8, 0xFFFFD000C66B5CF0)
Error: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED_M
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 system thread generated an exception which the error handler did not catch.
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 Wed 9/30/2015 10:34:06 AM GMT your computer crashed
crash dump file: C:\Windows\memory.dmp
This was probably caused by the following module: ntkrnlmp.exe (nt!KeBugCheckEx+0x0)
Bugcheck code: 0x7E (0xFFFFFFFFC0000005, 0xFFFFF8033132E85A, 0xFFFFD000C66B64E8, 0xFFFFD000C66B5CF0)
Error: SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
Bug check description: This bug check indicates that a system thread generated an exception that the error handler did not catch.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.
On Wed 9/30/2015 8:32:48 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\093015-14156-01.dmp
This was probably caused by the following module: win32k.sys (0xFFFFF960001BC6A7)
Bugcheck code: 0x50 (0xFFFFF901428944C0, 0x0, 0xFFFFF960001BC6A7, 0x0)
Error: PAGE_FAULT_IN_NONPAGED_AREA
file path: C:\Windows\system32\win32k.sys
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: Multi-User Win32 Driver
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 a standard Microsoft module. Your system configuration may be incorrect. Possibly this problem is caused by another driver on your system that cannot be identified at this time.
On Tue 9/29/2015 8:02:25 PM GMT your computer crashed
crash dump file: C:\Windows\Minidump\092915-13000-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x14F9A0)
Bugcheck code: 0x139 (0x3, 0xFFFFD001DA5EA820, 0xFFFFD001DA5EA778, 0x0)
Error: KERNEL_SECURITY_CHECK_FAILURE
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
Bug check description: The kernel has detected the corruption of a critical data structure.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.