Alienware X51: Auto Reboot / Display Driver stopped responding and has recovered / Internal HDD not found

I have three intermittent problems that has plagued me for the last 9 months with the X51.

1. The system Auto Restarts itself with a Bluescreen error and Mini Memory dump once in a while randomly (i.e. when I am using Firefox (hardware acceleration turned off), gaming and even when idle.) I checked my windows log and it has occured 43 times.

2. My screen turns blank and turns back on with the pop up: "Display Driver stopped responding and has recovered". Display driver NVIDIA Windows Kernel Mode Driver, Version 310.90 stopped responding and has successfully recovered."

3. The scariest one is that it suddenly screens the "Cannot find internal HDD" error screen of death, and doesn't allow me to reboot for awhile. This does not happen as often as 1 and 2, and is quite a rare occurence. But like seeing a RRoD, even once can scare you.

My Alienware X51 comes with Intel i5, Windows 7 64 bit, 8 GB RAM, and GTX555. It had its motherboard replaced the first week I got the system due to intermittent shutdowns as the motherboard apparently did not use the fan on the GPU and it was getting overheated. These shutdowns occured within an hour of booting up. The change in motherboard seems to have solved this problem and I am grateful.

What I have done to address 1, 2 and 3, is what I have found in these forums:

1. Update to latest BIOS for the system (A11)

2. Uninstall Video Driver completely and Reinstal with latest driver NVidia Geforce Version 310.90 released in Jan 2013

3. Run AlienAutopsy full diagnostics which passed all the series of test on the Motherboard, GPU, RAM, etc.

4. Defrag and McAfree scan the PC just to make sure.

5. The PC is placed firmly on the desk and has good air circulation and is kept clean.

6. Lastly will be going back to try the Boot F12 Dell Diagnostics, just saw this recommendation.

Ths thing is the system is able to handle many of the games I throw at it well (i.e. Diablo 3, GW2, Starcraft 2, Borderlands 2, etc). I monitor the GPU fan speed and all seems in order during gaming, and most of the time all is well. So it drives me nuts when I leave the computer absolutely idle for a toilet break and comeback to see that it restarted itself and I have to log in again.

I have fallen short of opening up the system myself as I do not have the anti-static bands and mats always recommended and since the system is still covered under warranty, this does not seem worth the risk. I know this has been suggested to check the wiring and seating of the devices.

I am posting in this forum as I want to check if I am missing out anything before contacting Dell. If Dell sends a technician, I would need to take a day off just to fix it and thus want to provide him all the information to properly fix it within that day.

Also this post seeks to document the experience in case other X51 users face the same issues.

- Your slowly losing faith but still hopeful Dell Customer

PS: I am jealous that the new models get the 1.5 GB GTX660! But I will be sufficiently satisfied if my above concerns are fixed.