The COM port (or Serial port) is rarely used nowadays since USB printers and mice, and ethernet modems became common alternatives. If your PC doesn't need it, you can disable it in Control Panel>System>Device Manager. You will probably see two com ports listed there if you expand that category. Double-click the first one (COM1) and select "Do not use this device (disable)" and click 'OK'. Then re-boot.
Disable COM2 the same way if that's not used either, because apart from your hibernation issue, disabling unused ports frees up resources for use elsewhere on your PC.
Disabling it if it's not required means it's drivers will not be loaded each time you boot so it should no longer interfere with hibernation.
Just be sure you don't need that COM2. I don't use either of mine so it's quite likely you don't either.
In any event, it's easy to re-enable if you need to, just go back to where you disabled it and choose "Use this device (enable)".
Edited by pip22, 27 November 2006 - 02:01 PM.