Right now I have about $800 as my safety and I plan on buying a new and my first gaming computer by the end of December. I plan on also getting a seasonal job so I would probably have more, but I don't plan on spending more than $900 on a computer, since I would most likely get a netbook or a laptop for my college work. I ordered Windows 7 32bit but I plan on buying the 64bit because I just found out what the difference was. I need the computer to be able to run high end games smoothly as well as Autocad.

This is the sysreq for Autocad
http://usa.autodesk.com/adsk/servlet/pc/index?siteID=123112&id=13784795

Just the tower or do you need monitor/speaker/keyboard/mouse/anything else I should know?

I recently got a new mouse and a monitor. I don't really use speakers, so I guess I need the keyboard and the tower.

Okay, here we go:

DVD: http://www.newegg.com/Product/Product.aspx?Item=N82E16827106334
Simple DVD drive and burner. SATA interface, so no messing about with ribbon cables which are ugly and old.

Case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811119137
Coulda seen this one coming with one eye tied behind your back. Its the Ex Signature Case, the CM RC690. Its the best mid tower around, Merrell recently built his new system with one, and I'm sure he can back me up on my ringing endorsements for this lovely case. <3

HDD: http://www.newegg.com/Product/Product.aspx?Item=N82E16822136320
Another, but more recent Ex Signature component, the WD Caviar Black 500GB. It slices, it dices, its the fastest series of 7200RPM SATAII drives around. I have one myself and I am very pleased with it.

GPU: http://www.newegg.com/Product/Product.aspx?Item=N82E16814150436
HD4870 1GB. XFX is offering this very nice model at a low price with free shipping. XFX is known for their good warranty service and quality products. They're one of the best in GPUs.

PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817371016
Antec, although making god awful hipster cases, makes great PSUs! 550w @ 65$ w/free shipping? A steal.

Keyboard: http://www.newegg.com/Product/Product.aspx?Item=N82E16823109149
This is really a personal preference thing, and I HATE fancy keyboard. I like something nice and simple that gets the job done. This was cheap and no nonsense, so I picked it. Feel free to spend extra on some silly LED/extra function key one or what have you.

RAM: http://www.newegg.com/Product/Product.aspx?Item=N82E16820220426
This is the bad news point. DDR2 prices have started to rise again, and this really harshes my mellow since the current i5/i7 DDR3 using chips are IMO not worth it. Sandy Bridge is coming, but it isn't here yet. Patriot is a good company and Viper is a good series. Highly recommended, if I had some cash, I'd probably pick up this kit myself.

Mobo: http://www.newegg.com/Product/Product.aspx?Item=N82E16813136053
Now THIS is good news. DFI's LP DK P45-T2RS is the next step up of my board, the LP DK P35-T2RS. DFI makes some serious boards, and they've got looks too. Great price, with free shipping, absolutely out standing.

CPU: http://www.newegg.com/Product/Product.aspx?Item=N82E16819116091
Its an E6300. It isn't going to be setting any benchmark records but these babies overclock like nobodies business. Check the reviews to hear of people cranking them up. I'd say you could get 3.6-3.8GHz out of a good chip.

CPU Cooler: http://www.newegg.com/Product/Product.aspx?Item=N82E16835233003
Another time honored Ex component, Xigmatek's HDT-S1283. One of the best LGA775 coolers around, it also has a nice and low price tag.

So what does this all come out to?
$778.04 after tax and shipping based on my zip code.

If you need any changes / further information, just ask.

From what I've heard, there are no 32-bit or 64-bit specific keys for Windows 7 or Vista. The keys are only specific to which OS or which level of the OS it is for (like Home Premium, Professional, or Ultimate).

I hate USB interface keyboards. They tend to be more faulty then P/S interface keyboards. Alot of keyboards I've tried on USB interface couldnt press more than 6 keys in any combination for USB interfaces. That becomes problematic sometimes.

Correct. I think I remember having the option of installing the 32 or 64 from the same disc.

Hmm I've been using USB keyboards for years and years, and I don't think I've ever had an issue with any of mine (with the exception of the first time I built my PC and the BIOS didn't recognize the keyboard at first).

That clocks to 3.8? Oh god. That is ridiculously cheap. Ex, you amaze me with how you put these builds together

3.8 is a conservative estimate for someone who is using a guide. A more experienced user could possibly get 4GHz+ out of one.

@USB Keyboards:
I switched to USB peripherals in 2004. I have never had a problem.

I use a USB mouse an dkeyboard, never had any problem.

Is 4 gb ram enough for today's gaming?

How much would it add to double it?

No official disc has both. Any unofficial disc having both will be missing the recovery options for one of them (will be missing 64-bit recovery options most likely, since the disc will likely be made to work on computers that can't run 64-bit). Official unmodified Windows 7 discs will also only let you install one version of it, even though each actually contains at least Starter, Home Basic, Home Premium, Professional, and Ultimate.

It will add double whatever the price of the RAM currently is.

4GB is more than fine. If you want to put in the extra $75, go for 8GB, but it really isn't necessary.

Yes, and you'd be looking at another 80$ probably.

4GB is more than enough for anyone who isn't doing 3d modeling.

You may or may not notice that 2-3 months ago, that same 2x2GB kit would've been 58$ instead of 78$. Let me break down for you what happened:
DDR2 became the most mainstream standard of RAM, replacing DDR and DDR3 being too new. It was over produced at low cost and so sold cheap.
Smart people stocked up.
Inventories started to empty, DDR3 became more in use, though still not the majority leader, as DDR2 still is, but DDR2 now an outdated tech, needed to be reproduced, which meant a higher production cost again since they weren't going to make a metric fucking ton of it this time, since you'd never sell it all.
Price went up.

When you see some prebuilt system touting 8GB RAM, they're using 4x2GB sticks @ DDR2 667 with 8-8-8-16 timings, which translates to absolute bullshit. DDR2 667 should run no higher than 4-4-4-12 timings, DDR2 800 5-5-5-15, and DDR2 1066 6-6-6-18. Thats absolute maximums. You can buy DDR2 1066 kits that do 4-4-4-12. Plus the prebuilt sticks have no heatspreaders on them either.

4GB is absolutely fine, and hell, I still recommend 32bit OSs for gaming/driver stability, so you shouldn't even be concerned. I'm using 2x1GB DDR2 800 @ 5-5-5-15 and I run Oblivion/Fallout 3/Half Life 2/Heroes Of Newerth/Risen/Any other game I want at max settings with no RAM limitation, ever.

lol, 2 GB may be enough for you... I have 4 GB in my computer (though only 3.25 GB available for now, because of 32-bit) and of that which is available, I'm very often using 70% or more. I suppose that is partly due to some things that are running in the background (though probably only a small part of it) but mainly because I often leave several things running at once. For example, I have 5 programs I manually run at startup and keep running all the time (though that still isn't much of it). I also currently have 32 tabs open in a web browser, and may have even more open while actively browsing a forum or other site with lots of links. In addition to that, I often run virtual machines for various purposes, sometimes running more than one at a time.

Okay, but with the current set up, I can upgrade it to 8gb easily right? I might have to use a 3d modelling program in few semesters.

Yes but expect it to get more expensive in the future. Another 2x2GB kit might run you 95-100$ as DDR2 gets phased out further.

Really, I don't see you needing any more RAM than that, its unreasonable to assume you're going to need 8GB of RAM, and I don't think you're going to be at all happy with a 64bit OS either, but I suppose I cant steer you away from that either.

If your goal ultimately is 3D modeling, a quad-core may be more suitable, too, right?

He can either have a gaming computer or a modeling computer. If he wants both, it isn't going to work at 800$.

What would the price be for both gaming and modeling? When you helped me set up my 800$ build for a pc, it looked like it could handle anything.