HD2600XT overheating

Well, if you are still running a 300W power supply it's possible that it's dieing and that would cause random issues as well. Even though the card requires a 300W power supply that would vary depending on what else you have in your system (ie extra hard drives dvd drives etc.) Whenever you run a power supply close to or at its maximum output, you will shorten it's lifespan. Even if it doesn't solve your issue, you may want to consider a replacement.

However, as far as heat goes if getting a new case would probably help if your case doesn't have decent airflow as it is right now.

That's the thing I have nothing else. Everything is as it was when I bought it prebuilt. All I added was the graphic card. I don't think getting a new case is an option, it's a prebuilt. Taking out everything and putting it in a new one isn't something I've ever done. Is the fan in my original post a good idea?

Clean the card, the 2600xt is well known to have a single slot cooler mainly the sapphire 2600xt which had a fairly crappy cooler over all. I suggest you clean the card and repast it and the temps should drop. Don't be half ass with it, really clean the dust out of it. If you want an after market cooler then the Zalman VF900 is the best fit for this card and are silent.

Thanks dude, any advice on how to clean the card? Should I take it out of the case completely? Kleenex? Vaccuum machine? What's "repast"?

So a case fan isn't necessary?

First you need to take the cooler off and take it apart then clean the dust from the heatsink as well the little fan. Once you are done get a brush and clean the dust from the rest of the card. Once done with both clean up the old stock compound and buy some arctic silver 5 (about $6 a tube) which is far better than what came with the card. Your temps should easily drop near to that of what you were getting when you first bought the card.

You don't want to use a Vacuum as they can generate a lot of static which you definitely don't want to be directing at any of your electrical components. Compressed air is your best bet for the larger pieces of dust. When it comes down to cleaning things you can use some Rubbing Alcohol and Q-Tips to clean the components.

Where can I get the Arctic silver 5? Also, what's the "old stock compound"? Difference between the heatsink and little fan? Also to take the cooler off I just pull it off? Just want to get my questions answered before opening the case cause then I can't google stuff.

The easiest place to get it would be online. However, if you're looking for some locally you could try the nearest Best Buy. They sometimes have it, other than that a local computer shop might have some.

Old stock compound is referring to the Thermal Paste they use in the factory. It's never very high grade and it's also not usually applied in the best fashion.

The heat-sink is the metal that makes contact with the chip to allow the heat to dissipate off of it, you apply your thermal paste to the chip so it can rapidly transfer the heat off of the chip, through the thermal paste, and onto the heat-sink. Most heat-sinks also come with fans(some don't but most do) and the fan is just there to move air across the metal so the metal cools down. If the metal were to heat up to the point of the chip it is cooling then everything will just continue to get hotter until something burns out. This leads to two options for heat-sinks. Either very large heat-sinks so it can dissipate heat better, or you use a fan to move air across the metal.

As far as removing your cooler, you'll need to take a look at it. Some are held on by clips, others screws, and still others are just snap-ons. You'll have to examine it and just be careful. Just pulling it off will probably end up damaging the card.

P.S. On a side note, you don't need a ton of thermal paste on the chip. More does not necessarily equal better. A thin layer of thermal paste will do just fine, adding too much can inhibit it's ability to transfer heat from the chip to the heat-sink.

Oh, convincing my parents to order online is a pain dude, do you think cleaning the heatsink and little fan alone would help? No local computer shops that I know of though I could ask a family friend who's good with computers.

Thanks dude sorry for all the questions, I'm gonna try cleaning the fan and heatsink tomorrow.

Unbelievable. Got lucky and found some MX-3 at a local shop for like 12 bucks. Found 99% alcohol at Loblaws. Had microfiber cloth already.

Did my thing, temps DROPPED.
Last year when I was playing Huxley gpu temp went up to 120 degrees C.
Today idle, it was 77 degrees.

After vaccuuming dust and repasting
75 degrees max after 10 minutes of NBA 2k10 on full quality.
52-59 degrees idle.

HUGE difference.