***** About the processor I was wondering if it supported Celeron's and or Pentium 4's, I might throw in a cheap 50-70$ Celeron like this one if it supports it.
Intel Celeron D 351 Prescott 533MHz FSB 256KB L2 Cache LGA 775 EM64T Processor - Retail http://www.newegg.com/Product/Product.asp?Item=N82E1681...
1. The case is nice and so is the PSU. I have a SmartPower 2.0 500W and it's a nice, quiet PSU. Your 400W should be enough as long as you keep the GPU to a reasonable size (your 7300GT is fine) in the future and don't try to overclock your CPU to stupidly high clock rates at the same time.
2. Motherboard: You seem to have had good luck with ASUS boards, and the P5B is a well-reviewed unit. It is a bit pricey, though, but not bad for a board with a brand-new Intel chipset. Be forewarned that it only has one IDE channel on it, so you can only put two ATA devices on the board without putting an extra IDE controller in it.
3. The CPU would work with that board okay. It's not that hot of a CPU, but it's 64-bit and cheap. However, I'd recommend a Pentium D 805 for about $50 more if you are going to be keeping that CPU for "a year or two." The 805 will feel much smoother than the Celeron and will play multithreaded games better than the Celeron.
A Core 2 Duo E6300 is $230 right now. Its MSRP is something like $180- if you wait a month or two, you can buy that and be much happier than you would be with a Celeron D 351 or the Pentium D 805.
4. Video card- looks good.
5. RAM: The 965 chipset supports up to DDR2-800 but the FSB is limited to 1066 MHz. So you can only use the bandwidth from a pair of DDR2-533 sticks to fed the CPU. The rest of the bandwidth can be used to feed the chipset and such, but unless you have an IGP, it's largely unused except if you want to overclock.
Corsair VS is good RAM. I have a 2x1GB kit of DDR 400 back from when it was cheap (damn, it's $192 now!!) So I looked at 2x512MB in DDR2-533, -667, and -800:
DDR2-533 CL4: $89.99
DDR2-667 CL?: $92.99
Corasir XMS DDR2-800 CL5 (no VS in -800 yet): $94.00 on sale ($109.00 regularly)
I'd recommend the XMS DDR2-800 *if and only if* you can get it at the $94.00 price. Otherwise, the VS DDR2-667 is what you'd like. It's always better to have just a bit faster RAM than the FSB if it's not too much more expensive than RAM of the speed that's equal to your FSB.
6. Hard drive: WD makes good ones. I have two and they are nice.
This computer would not necessarily kill your current rig as the 2.8 Northwood in your old rig is only a touch slower than a Celeron D 351 or a Pentium D 805. You'll have to put that Core 2 in there to see the real gains.
1) Will it all be compatible?
2) Would I beable to use a 80 or 100GB Maxtor IDE ATA133, and a IDE DVD Burner ( BenQ 1655 ), under my 1 IDE Channel if I decided to wait to get a SATA2 HD.
3) Will I still beable to use my Windows XP 32bit version using my new 775 computer 64Bit processor, and have all my programs still work. I beleive 64bit processors are also 32 bit correct? Because I dont plan on getting Windows Vista probably for years...
And when I get my new parts will I have to mess with BIOS features or anything else to get it all to read eachother?
The new rig with the Pentium D 805 or Celeron will be much faster than a Celeron 2.0. It just wouldn't be that much faster than a 2.8B Northwood, especially in games that are not multithreaded. Your encoders will GREATLY benefit from the PD 805 if they're decent multithreaded encoders.
You now would have less RAM in your new box than in your old one. But you do have two slots open for later. I'd generally recommend 2GB in a new build nowdays even with a 32-bit OS. 1GB will work, but under a lot of load, it can get used up. Just be judicious and remember that the price of DDR2 RAM will decrease over time. The Corsair XMS you highlighted is exactly what I meant. It's higher-grade RAM than the VS, so the 1.9 rated volts means that you could run the RAM at 1.9V if you wished to overclock or tighten timings on it and the extra 0.1V would not hurt it, but 1.8V (the DDR2 spec) would work fine at default settings.
As to your questions:
1. It should all be compatible. Your board would support a 533/800/1066 FSB LGA775 processor and the 965 chipset supports dual and single core chips. The RAM is DDR2-667 or -800 and the chipset supports it natively. The PSU and case and board are all ATX and your PSU has enough juice.
2. You can use your ATA HDD and DVD burner on that one IDE channel and be fine. You just cannot add any more ATA devices after that without adding a ~$30 PCI IDE controller card.
3. You certainly can run 32-bit XP on a 64-bit-capable chip and everything will work just fine as the chip can be run in 32-bit mode as well as 64-bit long mode. That's what >95% of people with 64-bit-capable chips do as a matter of fact. Few run Windows XP x64 as it requires 64-bit drivers and those are not easy to find and there are few 64-bit Windows programs. I've tried Vista x64 Beta and it is cruddy, really cruddy. Very slow and you need 3-4GB RAM to attempt to get decent performance. Oh, that and it's got enough of a ****load of DRM to make even the most draconian RIAA/MPAA/BSA exec jump for joy. I do nevertheless run a 64-bit OS on my computer, but I get around the driver and program issue by compiling everything from source code, which isn't exactly an option for Windows users for obvious reasons.