Charging an iPod on a PC without iTunes?

Without the iPodservice installed, which is done by installing iTunes, the Windows-based PC will just see the iPod as a removable hard drive. Just like any removable USB drive, it can be damaged if not properly ejected, hence the "Do Not Disconnect" warning.

To get the menu to come up you have to eject it. You'll notice that when you use your iPod in automatic mode and connect to a computer with iTunes the do not disconnect shows while the iPod is syncing and in communication with the computer. It automatically ejects once it is finished syncing but continues to charge. (It also remains on if the iPod is enabled for disk use or is set to manual update). It's worth ejecting the iPod and giving it a try to see if the same thing will happen on a PC without iTunes. However it may still need iPodService installed to charge, if that's the case then I'm afraid there's no way around it.