Often, the quickest way to identify what kind of slots your computer has is to open the case and look inside. However, if you have documentation for your computer (specifically for the motherboard), you can also find information on what slots it has there and looking there first is likely safer for inexperienced computer users than opening up the case.

Turn off the computer first, disconnect all power cords and suchlike, and lay the case down on its side on a solid, clean surface before opening it up. Do not touch any of the components inside, keep your cat/dog/ferret/wildebeest away while you're doing so, and don't drop anything (like your screwdriver) into the case or you could damage your computer. This is perfectly safe if you are careful and do it right - try not to put your hands actually inside the case unless you know what you're doing!

Slots are on the motherboard, and their shape tells you what kind they are. Check out the "what to look for" picture at this link.

While you're inside the case, take a look at your power supply (generally a large grey box with a fan hole on it in the top left of your computer case - it's what the plug attaches to). You may have to get a bit acrobatic to see the label on it (and you may need a small flashlight to see it), but it will tell how much power it has on the label on the power supply. You can then compare that number to the information given on the cards you're looking at to see if you have a good enough power supply for the card you're considering.

Even if your power supply has enough watts, it still may not be powerful enough to run your new card. Graphics cards also require that there be enough amps on the +12v rail. You might see information written like this: a 400W power supply with 26A on the +12v rail. The W is watts, and A is amps. Always check that whatever power supply you select meets the requirements of your card. Some of the most powerful and stable power supplies are made by PC Power & Cooling, Seasonic, Corsair, and OCZ. Of course, other companies make some good supplies as well, but if you see these brands you can’t go wrong. Other companies which manufacture some decent power supplies are Thermaltake, Enermax, Silverstone, FSP Group, and Antec. Do not think you can just buy the cheapest available power supply to run your card. Power supplies are very important in order to assure a stable computer. If your power supplies fails, you could fry every piece of hardware in your case.

Some higher end cards also require a direct connection to your power supply, meaning a wire from your power supply plugs into your card. Even if you think your power supply can handle your newer card, it is important to check that your power supply has this ability, if the card you want requires this.

Graphics cards will range from around $50 on the low end to over $1000 for the cutting-edge cards. Generally, though, you can purchase a decent card for around $100, though you may find a deal and get it for a little cheaper, or you may want to spend a little more and get a card that will last you longer and be more powerful. If you’re paying more than $500, you’re either getting a bad deal or you’ve found a card intended to do things like create 3d models (CAD) instead of play games. Nvidia Quadro cards are an example of this.

The system requirements for Sims 2 are listed here - note that the requirements for the expansion and stuff packs are different, and the guide includes the minimum system requirements to run the game. Just because it's listed there doesn't mean it will run well (the Geforce 2 being a good case in point).

However, it's a good starting point for research - start at the higher end of the supported cards listed (i.e. Geforce 9600 rather than Geforce 6200) and start researching what they can do, how much they are, etc. If you play other games, find their system requirements to make sure you're looking at supported cards for them as well.

The manufacturer's website is not a good place to look for information on the card's capabilities - even for old, crappy cards, they'll have text that tells about its dazzling, stunning graphics, and while it may have been true 5 years ago, it's not now.

A better test is to search for benchmarks and reviews for your card by Googling (for example, "GTS 250 Review"). Benchmarks are tests that people have done with the card using different games and settings to see how well it performs and offer a great comparison to help you make an informed choice. Higher framerates (the amount of times it draws the screen per second) means better performance.

While you may not find benchmarks done on Sims games, but you'll still be able to get a general idea of how strong one card is compared to others.

Video cards, more than any other component, will generate a LOT of heat, especially when you're playing a high-graphics-strain game (like The Sims 2). Your computer may not be able to handle this kind of heat, and if your graphics card overheats, it can damage or even ruin it - and other components like your motherboard!

To find out how hot your graphics card (and other hardware inside your computer) is running you can use a program such as this one. Check your temps while your computer is not been on long or not doing much. Leave the temperature monitor program running while you play your most demanding games/programs for a while, and then check again then see how hot the card is getting. Your card may be fine until you start to do some more demanding activities, like games, or you might find out that your card is running too hot all the time. Some cards run hotter than others, especially the higher end more powerful cards. Generally speaking, as long as your card is under 90 degrees Celsius it should be ok. Excellent cooling will keep most cards under 60 degrees celcius, but if you have a particularly high end (powerful) card, it is not uncommon to see much higher temps.

If you want to reduce how hot your card gets, there are some things you can do. It is always recommended that you not place anything in the slot directly below where your graphics card is. There should be an open slot between your card and the next anything you have installed. There will be a metal cover over slots which are not in use. Remove this cover on the skipped slot to create better airflow.

Over time, dust will accumulate in your computer. This dust can really hurt your computer's ability to keep itself cool. The best way to clean your computer is by first turning it off, and disconnecting all power cords. Before you open your computer, make sure you have it in a nice open area where nothing is going to fall into it or knock something inside it. It is best to work on a hard surface and not on carpet, if possible. Shocking your computer with static electricity can damage it. With your case open, use a can of compressed air to get the dust out. Never use water or other liquid cleaners inside your case . Take particular care to clean all fans, including the one inside your powersupply and on your graphics card (if your graphics card has a fan.. some do not.) Try to catch the dust bunnies hiding in corners and smaller places. Some professionals will reccomend using a vaccuum to suck dust out, but this can be dangerous as it could pull something loose or even suck up a small component! For these reasons, the mods of this forum feel that compressed air is the best way to go.

If temps are still not acceptable you might invest in a special gpu cooler, such as this one. Always check to make sure the cooler you are buying is compatible with your card, and that the power adapter on the fan can be hooked to either your motherboard or your power supply.