Outlook – Excel Attachments not opening

I am having a problem opening Excel attachments in Outlook 2002. The operating system is Windows XP Pro. Every time I try to open an Excel document, Excel opens but does not open any workbook, and Outlook displays a message: “The system cannot find the file specified”.

I have tried reloading Office and I have used the TweakUI powertoy under XP to repair icons.

Any suggestions?