I have had 3 of these events over the last month and a half and they happen overnight after I've gone to bed.  The machine reboots and creates the bugcheck event in the morning when I try to access the PC.  This is a new Win 8.1 desktop PC from early May.  Last two occurrences were June 4th and June 15th.  I'm not sure how to look at the dump files so maybe someone could help me out?  Here is a link to a folder on onedrive that I've put the dumps from the Minidump folder into a Onedrive folder here: add http: to //1drv.ms/1LbbTMC to view the files.

Thanks!

Here is the text from the last bugcheck event:

Here is the text from the kernel power event:

0: kd> .bugcheck
Bugcheck code 1000007E
Arguments ffffffff`c0000005 fffff801`e5b31160 ffffd000`219b29e8 ffffd000`219b21f0

0: kd> .exr 0xffffd000219b29e8
ExceptionAddress: fffff801e5b31160 (atikmdag+0x00000000000cd160)
   ExceptionCode: c0000005 (Access violation)

0: kd> .cxr 0xffffd000219b21f0
rax=0000000000000000 rbx=0000000000000000 rcx=0000000000000000
rdx=0000000000000000 rsi=ffffe001e9b89df8 rdi=0000000000000001
rip=fffff801e5b31160 rsp=ffffd000219b2c28 rbp=ffffe001e9b89df8
 r8=0000000000000004  r9=7fffe001e41c6340 r10=ffffe001e41c6340
r11=7ffffffffffffffc r12=ffffe001e3185010 r13=0000000000000000
r14=0000000000000001 r15=ffffe001eb23c3c8
iopl=0         nv up ei ng nz na pe nc
cs=0010  ss=0018  ds=002b  es=002b  fs=0053  gs=002b             efl=00010282
atikmdag+0xcd160:
fffff801`e5b31160 488b4130        mov     rax,qword ptr [rcx+30h] ds:002b:00000000`00000030=????????????????

0: kd> lmvm atikmdag
start             end                 module name
fffff801`e5a64000 fffff801`e6ce8000   atikmdag T (no symbols)           
    Loaded symbol image file: atikmdag.sys
    Image path: \SystemRoot\system32\DRIVERS\atikmdag.sys
    Image name: atikmdag.sys
    Timestamp:        Thu Nov 20 21:30:27 2014 (546EA3C3)
    CheckSum:         0121F198
    ImageSize:        01284000
    Translations:     0000.04b0 0000.04e4 0409.04b0 0409.04e4

0: kd> .bugcheck
Bugcheck code 1000007E
Arguments ffffffff`c0000005 fffff801`e5b31160 ffffd000`219b29e8 ffffd000`219b21f0

Reason for bug check was an access violation.

0: kd> .exr 0xffffd000219b29e8
ExceptionAddress: fffff801e5b31160 (atikmdag+0x00000000000cd160)
   ExceptionCode: c0000005 (Access violation)

Looks like the AMD/ATI video card driver was responsible for the access violation, but why?

0: kd> .cxr 0xffffd000219b21f0
rax=0000000000000000 rbx=0000000000000000 rcx=0000000000000000
rdx=0000000000000000 rsi=ffffe001e9b89df8 rdi=0000000000000001
rip=fffff801e5b31160 rsp=ffffd000219b2c28 rbp=ffffe001e9b89df8
 r8=0000000000000004  r9=7fffe001e41c6340 r10=ffffe001e41c6340
r11=7ffffffffffffffc r12=ffffe001e3185010 r13=0000000000000000
r14=0000000000000001 r15=ffffe001eb23c3c8
iopl=0         nv up ei ng nz na pe nc
cs=0010  ss=0018  ds=002b  es=002b  fs=0053  gs=002b             efl=00010282
atikmdag+0xcd160:
fffff801`e5b31160 488b4130        mov     rax,qword ptr [rcx+30h] ds:002b:00000000`00000030=????????????????

rax/rcx are non-volatile so we cannot check their contents, therefore we don't know why the violation occurred. We can guess however that it's a bug in your AMD/ATI driver causing one of them to be invalid as far as setting rax to the value at address rcx+30 goes.

0: kd> lmvm atikmdag
start             end                 module name
fffff801`e5a64000 fffff801`e6ce8000   atikmdag T (no symbols)           
    Loaded symbol image file: atikmdag.sys
    Image path: \SystemRoot\system32\DRIVERS\atikmdag.sys
    Image name: atikmdag.sys
    Timestamp:        Thu Nov 20 21:30:27 2014 (546EA3C3)
    CheckSum:         0121F198
    ImageSize:        01284000
    Translations:     0000.04b0 0000.04e4 0409.04b0 0409.04e4

2014 dated. Update to latest or if already latest, roll back til cra