Since Windows Me, Microsoft has included support for ZIP files in the system, allowing users to browse ZIP files as folders. Nowadays, WinRAR has become the most popular compression software, and it's likely that you have installed this software on your system. To disable the ZIP file functionality, you just need to unregister zipfldr.dll. Click "Start → Run", then enter "regsvr32 /u zipfldr.dll" (excluding the quotes, same applies below) in the Run input box, and press Enter.