-o[-] Overwrite existing files without a prompt (automatically reply "Yes" to each overwrite prompt). Use the optional "-" suffix to automatically reply "No" to each overwrite prompt.
wzunzip -o "c:\my documents\spring2005.zip" c:\semesters\spring05
Extract all files from the Zip file c:\my documents\spring2005.zip into c:\semesters\spring05 including those files with the same name as files that already exists in that folder.
wzunzip -o- "c:\my documents\spring2005.zip" c:\semesters\spring05
Extract all files from the Zip file c:\my documents\spring2005.zip into c:\semesters\spring05 except those files with the same name as files that already exists in that folder.