I decided to try the "S1" standby mode in the BIOS settings on a Dell Dimension E310, which resumes quicker than the "S3" mode but seems to only shut the hard drive down while the fan continues to work, and probably the RAM and/or processor are active as well. Tried to switch back to S3 to make less heat and use less electricity, and even though it is set at S3, it's still executing S1.
Switching to S1, exiting and saving settings, restarting, executing standby through the OS, restarting again, switching back to S3, saving the settings, and restarting again doesn't help. Also tried flashing the BIOS (which has been up to date all along) and clearing CMOS settings via the RTCRST jumper. Any other suggestions would be appreciated! Windows XP MCE if it's relevant.
you could try popping out the cmos battery for half an hour or so then put it back then try the reset cmos jumper again then boot up. although, i don't know if there are any ill effects from taking out the battery, you might want to research that first. also, when using the jumper do you leave it in the reset position for a good 10 seconds or just push it on the n take it off?