Cannot open embedded file in compatibility mode

[swampydrill]

I have a ledger / spreadsheet in excel whereby I embed receipts that I have incurred, these are always pdf files. I recently had to buy a new laptop which has windows 8.1 and 64 bit op system, on this I installed office 2013 professional, when I try and open a embedded pdf file it says cannot open source application, as the spreadsheet was started in office 2003 and so is now working in compatibility mode, is this why I cannot open the pdf files? some of the embedded files have either got t adobe logo on them or they have the actual receipt as a icon, the ones with receipt as the logo/icon open up but not the ones with the pdf icon. Any suggestions would be appreciated.