For a few months now, my computer's been shutting off completely after playing World of Warcraft for 30 minutes to an hour or more. Since then I have opened up the case to clean the inside free of dust regularly, as well as cleaned the heatsink and the heatsink fan, but it still shuts off, which leads me to believe that I'm overclocking my graphics card.
Computer system: Dell Inspiron 530
Current Graphics card: ATI Radeon HD 2600 XT
I plan to replace the graphics card and possibly the power supply if it requires it.
These are the cards I was looking at, but I was wondering if I could get a few tips regarding either.