Windows 7: BSOD (due to driver errors)

Hi,

it's not my first post concerning BSOD's
The last couple of days, my pc has bsod several times
sometimes there was the "system service exception" message, but often I read "driver_IRQL_not_less_or_equal"
some of the mentioned drivers were: ntfs.sys, win32k.sys etc. (because of this, the pc bsod also in safe mode)

I've added two minidumps

any help would be very much appreciated

thanks