Can not exit from Excel

[jimhabegger]

OS: Vista Home
Excel version: Microsoft Office 2000

If I try to exit from Excel using the red X button, or File, Exit, or Alt-F4, or the taskbar, nothing happens. If I try to close the workbook window using its X button, or create a new workbook, I get this message:

Microsoft Excel for Windows 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.

This just started happening yesterday, March 7. The only installations I know of that happened yesterday were a Java update and a Flash Player update.

The problem happens when I launch Excel from the start menu or application icon, and when I launch it by double-clicking on a workbook icon, with one exception. I have one workbook that I downloaded from the Internet some months ago. When I launch Excel by double-clicking on that workbook, I can exit normally. I've used that workbook many times since I downloaded it, and I've used Excel often since then, without ever having this problem until yesterday.