3d games/programs crashes at full screen in a powerful laptop

Hi, I bought a new laptop and it has a problem i discovered. I cannot return the laptop as it already past the returning date (30days). The problem is discovered last week after i installed lots of games.

My laptop crashes at full screen mode on any games i installed. At first I blamed the game, but after installing lots of games and tried every single one of them (age of empires3, medieval2tw, COD, black and white 2, red alert3, etc.). After this, I also tried to use some 3d programs like the ones built with the latest Nvidia SDK with Direct3d 11 and still crashes. The crash (to be specific) is almost a crash to desktop (CTD) BUT, weirdly, it loads itself back and then loops again more like alt+tabing when ur in game(it's not sticky keys). However, the 3d programs like the one in NVIDIA doesn't ''alt+tabs'', it's a complete crash and the windows will then try to resolve it (which fails). It's a bit powerful laptop and here are my specs:
Windows 7 Home Prem 64bit
Core 2 duo t6600 2.20ghz
4gb ram ddr3
1gb Nvidia Geforce gt 240m
Supported by PhysX but Games requires DirectX so I installed it. Would it clash? I dont think so, coz you can turn off the physX gpu. and i tried that.
1tb HDD
Now, the things that I have tried are:
Update/install my video card driver, chipset and was going to update my BIOS (which is the latest so that's why i did not).
Installed the directX 11 (SDK), and even tried the Direct x 9.0c.
I even clean up my system by reinstalling windows and everything.
I don't think it is a compatibility issues as I've played these games on a different laptop with the exact same system (my first laptop before, I exchange it for it is has a faulty keyboard and same windows)
As you can see I am getting bad luck from where I bought my laptop. Yes, it is a refurbished laptop from a big name retail store.
I already contacted the Manufacturer and they couldn't help me because it involves third party software. However I told them that I highly believe it is a hardware issue and the sick bastards replied with: ''ask for advice from your local technician.'' Wth?! I well try to settle a score with them tomorrow but for now, I want your expertises.

make sure all vents and fan intakes are not blocked, download and run HWMonitor and run a game and tell use all the min and max temps

Ok, I have the temperatures of during normal use (no heavy graphic usage), During play, and during crash. you think my Card is overclocked? No blockage of the vents btw. Room is below 30 degrees C.
Attached are Printscreen of the CPUID monitor.
If you dont want to view, ill sum it up.
Normal temp:
Mobile Core 2 duo... Value..... Min.....Max
Core#0.................49C (120F) 49C 60C (140F)
Core #1............... 50C (122F) 50C 55C (131F)
Nvidia Gefore GT240m
GPU Core............ 42C (107F) 42C 44C(111F)

For temp during game play (no crash), has about the same with +3C on the Cores from normal temp (no heavy 3d) and +2 on GPU Value temp.

During crash however, Core#0 jumps to 74C(165F) value, MAX is 79C (174F), Core#1 has 70C value and 78 Max.
GPU Core has gone upto 57C (134F) with a Min 41C(105F) and 63C(145F).
One attempt I've seen GPU gone upto 60 value and 65Max