If you are having trouble updating HackShield, please follow these steps:
1. Reboot your computer
2. Erase all the files in the HShield folder in the MapleStory installation folder.
3. Download http://maplestory.nexon.net/download/hackshield/HShield.zip.
4. Copy all the files and paste to the HShield folder inside the MapleStory installation folder.
5. Run the game.
If the game still doesn't run follow these steps:
1. Uninstall MapleStory by going to the Control Panel from the Start menu, then fully uninstall MapleStory.
2. After uninstalling through Control Panel, go to your MapleStory folder which is usually in the C: Drive (C:\Nexon\MapleStory), and make sure all files are deleted.
3. Install the full client.
4. Reboot your computer.
If you are still experiencing problems, please report it here.