My iPod Shuffle is not charging from USB

On the shuffle's Summary screen in iTunes, there is an option (checkbox) to Enable disk use. As a test, turn ON that option and Apply. (If Manually manage music is enabled, disk use is already enabled.) Does that make any difference regarding this problem?

NOTE: When disk use is enable, the shuffle's light should continue to blink as a warning not to disconnect the shuffle; eject it before disconnecting. However, the shuffle is charging while the light is blinking, although it will not turn green (until you eject it).

I don't know where "fix" this will be (Microsoft, Asus, or Apple), but this may be what's going on...

When an iPod is NOT set to Enable disk use (or Manually manage music), iTunes only mounts the iPod's disk when syncing. The rest of the time, the iPod's disk is not mounted. There may be a "feature" on your laptop, and/or in Windows 8, that attempts to save energy by putting the USB port into a low-power mode, when the connected storage device (the iPod in this case) is not mounted. When iTunes unmounts the iPod's disk after syncing, it may look like an external storage device that no longer needs full power, even though an iPod needs full power to charge its battery.

When an iPod IS set to Enable disk use (or Manually manage music), iTunes keeps the iPod's disk mounted continuously. Therefore, the USB port stays at full-power mode and the iPod's battery is able to charge.

I know you said

I have disabled the USB suspension. Driver is not authorized to turn off the port to save energy.

but maybe that setting is not working properly (as it relates to iTunes/iPod), and that's the cause.

A desktop computer does not run on battery power, so it may not have this feature; saving energy is not a high priority when the power source is the wall outlet, not a battery. Or, Windows Vista may not have this feature. Therefore, the USB port gets full power whether the connected storage device is mounted or not.

One additional test you can try is to see if it makes a difference if the laptop's power adapter is connected or disconnected. When the power adapter is connected, the laptop has "unlimited" access to energy from the wall outlet (like the desktop), so maybe the USB ports stay at full power all the time.

Thanks Kenichi. This appears to have also solved my problem of my shuffle continuously syncing. Now it seems to be charging. Good advice.