Spreadsheets have lost format

I was working on my accounts spreadsheets. I then opened the spreadsheet yesterday and the format has completely gone mad, Its lost all of its orginal format, is there any way I can recover back to its orginal format. If i attach the spreadsheet can someone take a look please.

Try a Detect & Repair:

On the Task Bar,
Help
Detect & Repair

You may need the original install media.

See if that helps.