Microsoft Office Excel has stopped working
 

I have just bought a new machine running Windows Vista Ultimate SP1 and I
have installed Microsoft Office 2003 SP3 and encountered a problem in Excel.

Whenever I was working on an Excel file and closed Excel by clicking "file"
and then "exit", the following error happened:

"Mircosoft Office Excel has stopped working. Windows is checking for a
solution to the problem".

After a while, another messge showed:

"Microsoft Office Excel has stopped working. A problem caused the program
to stop working correctly. Windows will close the program and notify you if
a solution is available".

And Excel was closed without saving any of my working.

However, if I exited Excel by clicking "file" then "close", there was no
error at all. I could then close Excel without any problem.

Please advise what the problem is.