This was addressed before, by me but a lot has changed and I am ready to move on this. My OS is XP Home. I am currently saddled with an ATI Technologies, Inc. RAGE XL PCI video card with a memory of 8mb(bummer). I want to upgrade to 32mb or 64 mb. Is this possible and what is the minimum power supply for each? Will I have to upgrade anything else? (3 questions for 1 problem....wow) .
I have an etower 733i with an Intel celeron 733MHz(11x67)processer. My RAM is 384mb with an update-ready 512 available. HD Space is 20gb with 12.5 available.
My biggest worries are whether it will fit in my chassis, cost and what other ugrades will be necessary. Especially the power supply.
This machine has the etower chassis but was specially built with some etower parts and some others. For instance...the motherboard is an Imperial/Glendale rather than the stock emachines cognac board. The I/G motherboard indeed has 2 slots which support up tp 256mb RAM each. I have run a "Belarc" test and an "Everest" test and both are in agreement on specs. I know the power supply is very small, but I do not have the output on it. I think it needs an upgrade to support a 32mb or 64mb card. I am willing to go there. I just don't want to go to extravagant places. Windows XP is operating really well on this computer. I upgraded from WinMe becaust WinMe was flaky.....inconsistant and many programs would not work properly. Please see my questions above and advise accordingly. Thank you.

32 or 64Mb for graphics is still VERY SMALL. I would shoot for 128 minimum, or even 256. There are several cards at Newegg for less than $50.

You have to determine 3 things - your budget, the type interface your motherboard supports, then the PSU.

If your motherboard supports AGP or PCIe, use that. If not, there are still several PCI cards to choose from. If you find a card you like, check the maker's site - they generally list the minimum PSU requirements or you can use a PSU calculator - here's my canned text for determining your PSU needs.

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Use the eXtreme PSU Calculator Lite to determine your power supply unit (PSU) requirements. Plug in all the hardware you think you might have in 2 or 3 years (extra drives, bigger or 2nd video card, more RAM, etc.). Be sure to read and heed the notes at the bottom of the page. I recommend setting Capacitor Aging to 30%, and if you participate in distributive computing projects (e.g. BOINC or Folding@Home), I recommend setting TDP to 100%. These steps ensure the supply has adequate head room for stress free operation and future demands. Research your video card and pay particular attention to the power supply requirements for your card listed on your video card maker's website. If not listed, check a comparable card (same graphics engine and RAM) from a different maker. The key specifications, in order of importance are:

1. Current (amperage or amps) on the +12V rail,
2. Efficiency,
3. Total wattage.

Then look for power supply brands listed under the "Good" column of PC Mechanic's PSU Reference List. Ensure the supplied amperage on the +12V rails of your chosen PSU meets the requirements of your video card. Don't try to save a few dollars by getting a cheap supply. And don't count on supplies that come included with a case. They are often underrated, budget or poor quality models "tossed in" to make the case sale. Digital electronics, including CPUs, RAM, and today's advanced graphics cards, need clean, stable power. A good, well chosen supply will provide years of service and upgrade wiggle room. I strongly recommend you pick a supply with an efficiency rating equal to, or greater than 80%. Look for the 80 Plus - EnergyStar Compliant label. And don't forget to budget for a good UPS with AVR (automatic voltage regulation), as surge and spike protectors are inadequate.