BSoD / Windows 7 Ultimate x64

[sioux]

In the last 5-6 days i had two BSoD.
Do you have any idea what could be the causes ?
I attached here 2 printscreens.
Any ideas / advices / are welcome, thank you
http://postimg.org/image/uxzp3t2kt/
http://postimg.org/image/ai7z7i9hz/

 

[Smoove910]

do you have an event viewer or a system log to reference? Might cue you in on what the prob is/was

 

[sm625]

Try physically disconnecting your DVD drive. (Assuming you arent using it when the crashes occur.)