My current PC contains:

Athlon XP 1600+ (1.4 MHz)
Gigabyte motherboard
768 meg ram (I think it's PC2100?)

All of the other cards and miscellany are newer. I'm not at home now, but I know I'll be saving the 120 mB Maxtor, the 40 mB Western Digital, the graphics card (don't remember much about it to tell the truth). System has a DVD-ROM and a DVD-RW, and USB 2.0 PCI card. The 1394 card appears to have died. Doesn't show up in Device Manager anymore.

Anyway, it's the motherboard and CPU I want to replace, but alot has changed since I built this 2-3 years ago. I don't know how to match up the CPU and motherboard, and what type of memory I'll need to buy.

I'm doing this because the computer still isn't acting right after I replaced the boot drive. It had been spontaneously rebooting (I've seen this described elsewhere on this site), and when I went to reformat the drive to do a clean install, it couldn't complete the format.

The new drive and clean install fixed the spontaneous reboot problem, but now the computer sometimes freezes up in the boot process, before anything comes up on the screen. When it does work, it seems slower than before, and as I mentioned, the 1394 card isn't recognized.

What I want to do is replace the board, CPU, with something more current, but still inexpensive, and give it about 512 to a gig of memory. I want to do it for around $300. Any suggestions?

Ok, the price range will allow you to keep your Video card.

First thing you want to think about is what exactly do you want to move to. A fast Athlon or Pentium. I would assume Athlon or Sempron since that is what you are currently using.

Next is your memory. You stated 512, so that would be easier to fix in that price.

Any new MB will already have USB2 and maybe 1394.

Use Pricewatch or Froogle to do quick item search and price comparisons.

Here is what I found at Mwave (I like them but dont go there just because.. Shop around!)

The Asus A7N8X-E Dlx (http://usa.asus.com/products/mb/sock...d/overview.htm) has USB2.0 and Firewire on board.
It is a good board and will use your video card, HDDs and Optical drives you already have. Mwave has it for about 86 USD.
Putting an Athlon XP 3000+ in it adds an additional 114 USD
Add 512 of generic DDR333 memory for 36 USD and the total price on their site comes to 236 before tax and shipping.

This was just an excercize and not something I would want you to just go out and do. What you should do is look at the old MBs still for sale, find the one that has AGP instead of PCI-x (new standard that the industry is going to) and if the motherboard still has 2 IDE ATA-100/133 connectors (You do not have SATA-150 drives)

These are, again, starting points. Feel free to ask more questions and welcom to DAL

So far, I'm liking your idea, but as you said shop around. The ASUS board seems to be packed with features. I found these at compUSA's website. I have a newspaper ad for a Athlon 64 3000+ / MSI motherboard for $199, but couldn't find it at their website.

Any pros and cons associated with these CPU/motherboard bundles?

http://www.compusa.com/products/prod...742&pfp=BROWSE

http://www.compusa.com/products/product_info.asp?product_code=319442&pfp=BROWSE

I didn't even think of compatibility with hdd and optical drives. Any with these?

The 2nd link took me to MS...Go figure. The MSI board looks OK. I am a bit reserved when it comes to integrated video. Too many on this forum and else where have had issues with disabling the onboard in favor of a better/new card.

With out knowing about your video card, AGP 2x/4x may be too limited for your current video (which you would then use just the onboard) The P4 2.26 with the MSI board, for 199 is about average to high average. You can look at Newegg, Tiger Direct, CDW, PCMall, etc. in the same venue as Compusa.

I generally will go with the strongest Processor I can then max the memory.
When it comes to the bang for the buck, AMD is providing it in the Athlon XPs.

Keep looking and remember to avoid as many pitfalls as possible, keep the hardware in mind of what you want to move over, the HDDs and Opticals. Most new boards will have IDE for the opticals, but may have moved off the Parallel IDE in favor of Serial IDE.

Is the Athlon XP 3000+ the fastest cpu that will ever fit in that ASUS motherboard?

Asus shows a 3200+ also fitting in it. Remember, these are the 32bit Athlons, the latest and most expensive are the 64bit.