I would still turn off this service:
You can check for pctspk.exe under Admin tools > services
You can turn it off & then set its' status to disable. (this is also reversable).
Since your system is on C:\ & your apps on D:\ it must be some program, rather than windows, that is triggering the chkdsk.
You might want to check what programs & services are starting at boot.
This is a good little tool for that:
Autoruns
You might also want to check your Disk Management by:
Disk Managment:
RT click
My Computer then click
Manage then
Disk Managment
Check to see that C:\ is indeed "Healthy (system)"
& see how D:\ is listed. Is it called "Boot" by any chance?
If you want to rerun:
"I then run CHKNTFS /? and got a load of info"
& post a screen shot we can look at that if you want.
But I suppose if chkdsk doesn't get rescheduled you should be ok.