iSpeech.org offers online text-to-speech conversion with several voice templates. I found it quite amusing and interesting to play with this feature. For personal use, sound pieces up to 1 minute are free. The idea to create Windows sounds with it was quickly born and I created the ones that you can download from here, called Windows Sounds iSpeech Female. Not all sounds “she” speaks are rated PG but they give a special and funny touch to your Windows events.
Just download the setup executable to install it in Windows Vista, 7, 8 or 8.1. The setup will creat a sound scheme “iSpeech Female” and sets those sounds as the current ones. You can always revert back of course or pick another sound scheme through Control Panel -> Sound -> Sounds.