stop 0x00000050 windows 7 64bit only on startup

Hi
Im getting a stop 0x00000050 windows 7 bsod randomly now for weeks.on startup
i have ran memtest86 boot version no errors chkdsk on all drives no errors
updated all drives rolled back updates done a clean install and im running out of ideas.
would really love some help guys thanks.
Im running a 4790k on a asus ROG hero vii with 16 GB of hyperx DDR4 and a GTX 660ti with a
Samsung 840 evo 250gb boot drive and a 1.5TB HDD for storage
ill attach mini dumb and rar file
look forward to hearing from you

Kenneth

Welcome to 7F. There is only one dump in your logs but looking at it I would suspect they're all the same.

Code:

*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

Use !analyze -v to get detailed debugging information.

BugCheck 50, {fffff8800af003f4, 0, fffff88009cbc988, 2}

*** WARNING: Unable to verify timestamp for IOMap64.sys
*** ERROR: Module load completed but symbols could not be loaded for IOMap64.sys

Could not read faulting driver name
Probably caused by : IOMap64.sys ( IOMap64+1988 )

This is blaming an ASUS service. You have a lot of ASUS software installed on your machine and it would be wise if you removed it. Do that and test stability then report back.

Not a problem, upload any new dumps from any subsequent BSODs.