as far as i can see its definitely the HFS+ drive. starting up with it in means it wont even get to the startup screen now, which is weird as originally it'd start up then crash. starting up without it and then plugging it in produces a crash within a couple of minutes. without the drive plugged in its completely stable.
the HFS+ drive is 6 months old, the exFAT drive at least a year and both were plugged in when using windows 7 for many hours on many days.
ive checked the driver on the exFAT drive, it says its up to date, but of course since i cant mount the HFS+ drive there's no driver to be updated.
if i cant fix it, is there any way in windows to mark the drive as not to start up (in windows only).