The Hacker Project - a free online game

If you are looking for a way to repair corrupt .xlsx file, you can try "Open and Repair" function of MS Excel. It is very simple and effective.

But if fails, you may try a third-party Excel file Recovery to fix corrupt .xlsx file and to recover your data from it.

You may try its free demo version first.

Visit- http://www.recoverydeletedfiles.com/excel-file-recovery-tool.html