Question : Update linked filenames in Excel 2007

I have a user with several large Excel workbooks who recently upgraded from Excel 2003 to Excel 2007.  He has begun saving his Excel workbooks with the xlsx extension, but this has broken several hundred links in one of the workbooks because the previously referenced file now no longer exists.

In other words, DATA.xls is now DATA.xlsx.  Any references in FORMAT.xlsx to DATA.xls are now broken.

What is the quickest and/or easiest way to update all of the external links to reference the renamed file, DATA.xlsx?

Answer : Update linked filenames in Excel 2007

>>  after restarting gets an error  System.ArgumentNullException' occurred in mscorlib.dll

This is because your file is blank and ReadLine() returns nothing, so null is being passed to Long.Parse(). You should consider checking the return of ReadLine() for null before passing to Long.Parse--even if you get the logic working correctly.

>>  it all works except when it tries to write to the file nothing gets written

What kind of app is this? A windows service?

>>  what os are you using

XP