If you’re Polish or any other nation that depends greatly on AltGr in your computer keyboard and moreover you’re using Windows 8 on a computer with Synaptics touchpad then you have probably lost your AltGr recently. This issue is caused by the latest update installed automatically by Windows Update. The issue revelas itself in a fact that you cannot use your AltGr (RAlt, right Alt) anymore. It starts working like your left Alt just opening menus instead of producing special characters like: ł, ó, ś, ć, ź, ż. Moreover if you use Ctrl+Alt instead of AltGr (btw. AltGr is just an abbreviation of these two key strokes) you get your diacritic characters back.
Fix is extremaly easy:
1. Uninstall Synaptics driver using Control Panel -> Add Remove Programs
2. Restart the computer
3. Go to windows update and force Check for new updates
4. See a list of updates, including those optional ones and you should find your Synaptics update.
5. Right-click and hide.