Hi, I have this problem: since I switched from Win XP to Win 7, when I try to open a file *.xlsx (Excel 2007) a Pop up windows appears that says: "filename.xlsx includes content unreadable. Retrieve the contents of the workbook? If the workbook comes from a trusted source, click yes". If I choose "Yes", file is opened completely damaged and unreadable. The only way to successfully open files is CLOSING Excel, and select the file name from Windows Explorer: in this way Excel starts automatically and opens the file perfectly. Someone can help me? It's impossible to work in this way! Thanks in advance.