Windows 7: Screen randomly turns black while playing games!

Hello!

So this is pretty recent. During the past week, my computer has constantly been crashing as I played video games.

Things you probably need to know:
This is a pretty old laptop.

Graphics card: ATI Radeon X1300 Mobility
Processor: Intel Core Duo 1.6Ghz
RAM:2 Gigabytes
Window's 7 32 Bit.

Okay, now about my problem.

So recently during the past 2 weeks, every time I played League of Legends, 10-30 minutes into the game my screen turns black and my computer chokes up and I crash. I can leave my computer on forever and I wont get any BSOD, but the screen will remain black.

So I hold the power button and restart my computer, however when it loads it tells me Windows 7 has experienced a problem, however it doesn't tell me what the problem is. And the vicious cycle repeats.

So at first, I thought, it could be the graphics card.

It's old. HOWEVER, I've ran league of legends for the past year and NOTHING happened until now. So... Still, I took no chances and I did a stress test on my graphics card, and it didn't crash. Now, maybe as League patched and updated the new effects may crash my computer. However, League of Legends isn't the only game I play. I also play the notorious Halo Combat Evolved Trial. OH yeah. That game designed, for Windows 98 WILL still give me the black screen and crash me.

So any ideas on why my computer is randomly crashing, I'd love to give you an error report, but even I don't have one.