If it has a dual core or better processor and 4Gb of RAM, it's still probably viable for most things other than action games. If so, then replacing the PSU with one about 500w might be the better move. I use this in both of my 10 year old computers. It's 450w "continual power" which is better than 500w "max power" rating used on many others. Antec is an excellent quality manufacturer of PSU. It's $38 with FREE SHIPPING.
This testing site below is a good and honest one.
"The Antec VP450 passed our tests with flying colors.
Efficiency was between 80.3% and 85.5% during our tests, which is outstanding for a budget power supply. The only reason this unit can’t get the 80 Plus certification is that only power supplies with a PFC circuit can be certified, as the 80 Plus certification requires a power factor of at least 0.900 at full load.
Voltage regulation was outstanding, with all voltages closer to their nominal values than required (three percent regulation), except for the -12 V output, which was still inside the allowed range. The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values.
Let’s discuss the ripple and noise levels on the next page.
Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple&rdquo
. The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.
The Antec VP450 provided ripple and noise levels within specs, as you can see in the table below.
We were extremely impressed by the Antec VP450 power supply, which proved to be an above average budget power supply.
Power supplies without a PFC circuit usually provide, at least at some point, efficiency below 80 percent. However, this simply didn’t happen with the VP450, which presented efficiency between 80.3% and 85.5 percent. This unit, though, can’t qualify for the 80 Plus certification, as a PFC circuit is required to obtain it.
In addition, most budget power supplies have a fake label that says the unit has two +12 V virtual rails, while in reality the power supply doesn’t have an over current protection circuit, which is necessary for the power supply to have more than one +12 V rail. This doesn’t happen with the VP450, which really has two +12 V over current protection channels.
With so many bad power supplies sold for USD 40 or less (several of which can really damage your PC due to voltages outside the proper range), the Antec VP450 is a terrific find. If you are building an entry-level PC that doesn’t require a lot of power, you and your wallet will be very happy with the VP450.
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Max Load is over 550w.