Is there a program to measure wattage used by the system?

[alternate]

Is there a program to measure wattage used by the system, i.e. how much watts my power supply gives, maybe even broken down into amps and volts?

Is there any other method to measure wattage?

:p

[Hagar]

That cannot be done. There is no hardware to measure amps in a PC.

There are cheap power meters (like E-Tech PM300) that can give you approximate power use for the whole system.

[Sylvander]

What about...
1. You leave the PC switched on overnight, with ALL other electrical appliances switched off and using no power, and take a KW-Hour reading at your home electricity meter at a noted time when going to bed.

2. In the morning, before any electrical appliances are switched on...
Take a 2nd KW-Hour reading at a noted time.

3. Calculate the KW-Hours used and divide by the number of hours to get the RATE [KW] at which power was being used.

4. The longer the period [number of hours] you do this for, the more accurate & precise the result is likely to be.

5. e.g. 100 watts used for 10 hrs = 1 KW-Hour [too small a reading, longer is better] = 1,000 Watt-Hours.
1,000 Watt-Hours divided by 10 hours = 100 watts RATE of usage [power].

6. This is not guaranteed to be a totally accurate measure of true electrical power usage because the POWER FACTOR may not be UNITY [1.000].
i.e there could be [is likely to be] INDUCTANCE & CAPACITANCE [as well as resistance] in the system.
These make the apparent power usage differ [slightly] from the true power usage.
[The resistive power vector is slightly out-of-phase with the apparent power vector]

Power factor correction (http://en.wikipedia.org/wiki/Power_factor_correction)
QUOTE
"When an electric load has a p.f. lower than 1, the apparent power delivered to the load is greater than the real power that the load consumes."