Studio XPS 1640 Wake Up Automatically

No, not immediately, my computer woke up at about 4 AM and I command 8 hours later.
Yes, I use an external wired mouse.

Oh! I think mouse was the problem really!
After your useful post and do command, in device manager, I looked power management option for mouse, and saw that "Allow this device to wake the computer" is checked!!
About nightly my computer woke up! Now, if for 2-3 days don't automatically wake up, meaning mouse was the cause of problem.
Thanks a lot bill, I hope this problem be resolved.


I will post here the result.
Thanks again.

Unfortunately my problem didn't solve

Dear mgorman87, thank you for your reply.
I think my problem solved here.

Best regards,
Nima