Energy usage before computer logs in

I have recently shared my printer, so I can access it (via a wireless router) with my laptop, in addition to the desktop (which is wired to the printer).

I have found that I don't even have to log into Windows (XP) for the printer to be shared, but I do have to turn on the computer itself. Parts of Windows load before logging in, and evidently that part that controls access to the shared printer does at that point.

Since I don't personally use the desktop for anything, I will often leave it turned on, but not logged in, so I can immediately use the printer from my laptop, for hours before someone actually uses the desktop.

My question--what is the energy use of a computer that isn't logged in? I use standby on my laptop all the time as a nice compromise between turning it off (no energy usage, but takes longer to access) and leaving it on all the time. How does the energy useage of a computer running XP, but not logged in, compare to standby or to having logged on and running the startup programs (like antivirus, etc.)? Even if I could print while the desktop was in standby, I wouldn't, because this desktop has always had problems resuming from hibernation and standby.

 

No the laptop is in another room--its connected via a wireless router.

Even 30% is a decent amount, although I was hoping for a bit more. On standby, the figures I saw for Dells was about 1/40 of the normal amount of electricity--below 5%; altough standby obviously would use less of the system than just not logging in.