The part about the email...doesn't make any sense, unless the email addresses she is using are incorrect. The fact that she can send and receive emails from others (along with receiving the spam we all get) rules out any trouble with the setup of the email program or the hardware used.
There are no different standards that I know of internationally for email, as can be seen from the fact that any forum/website has viewers/members from all over the world.
As for sound...the simplest approach is to go to Device Manager...and see if there are any yellow or red markings. If there are, then the drivers for that function need to be installed.
If Device Manager indicates no problems with the Sound, Video and Game Controllers...try uninstalling whatever audio device is listed, then installing drivers anew. Sometimes, when drivers are damaged, Device Manager may think that they are working as planned when, in fact, they are not.
Also...run through the XP Sound Troubleshooter, http://support.microsoft.com/kb/307918