If your laptop uses a 479 socket, none of the processors will work for you because your T9600 is soldered to the motherboard.
Now, regarding the Q9000, you could have used it, if your T9600 used a 478 socket.
It was good that you checked with Dell first. An upgrade processor must be compatible with the socket and BIOS. So, if Dell gave you the proper list of processors that would be compatible with their bios, assuming all used the 478 socket, you could have chosen from any of them. Alas, your T9600 could use either a 478 or 479 socket. The 479 socket is the show stopper.
Sorry for the bad news.
This message was posted on behalf of Intel Corporation
In regard to your equipment: Alienware M17x R1 and its own specifications.
I was able to confirm that your current chipset is:
System Chipset NVIDIA® GeForce® 9400M G
And also the specifications as the BIOS of your laptop will determine the compatibility with any type of upgrade. My recommendation will be to contact Dell to address this issue.