It is possible this excel file was written on an older or different version of microsoft excel ... e.g Microst Excel 2005 or perhaps by another program such as LibreOffice ... which is not compatible with the version of excel running on your windows 8 PC ( I'm assuming the windows 8 pc is running a post 2012 version of excel.
An extension is the part of the file that comes after the dot e.g
exampleessayongiraafes**.doc** - Is a word document
examplespreadsheetongiraffes**.xls** - Is a spreadsheet
examplepresentationongiraffes**.ppt** - Is a powerpoint
these extensions have changed over every edition of MS office .. please check the extentension of the file that wont open and file formats your version of excel will open e.g
.xlsx is an acceptable excel format for Microsoft Excel 2010 but not 1993 ... if you post you version of excel and the extension, I will be able to assist you further