Hi,

after more testing. I found that starting from our Netapp-Filer the problem was gone.
On the filer the option: cifs.smb2.durable_handle.enable was disabled.
After disabling smb2 on DCs kix32.exe also not opened.

From a german AD maillinglist i got the answer to test the following registry key:
HKLM\System\CCS\Services\LanmanServer\Parameters
Type: REG_DWORD
Name: DisableLeasing
Value: 1

After setting this key on all DCs tomorrow only 3 PCs ( from 300 ) holds kix32 open.