I have been tormented by Excel 2007 workbook open crashes since I installed Office 2007. I found a fix which I’ve had some success with, so I would like to pass it on to those of you who have a similar problem. When a workbook crashes, there is a good chance that Excel marks the file as “Disabled”. This black mark doesn’t always go away when you start having better results by applying other fixes. So its worth your while to follow the steps shown below to re-enable the file. This is no guarantee of a permanent fix, but it’s very much worth performing since as long as the file is marked “disabled” you will probably continue to have the crashes on startup. So here are the steps to take:

1.Click on the Microsoft button in the upper left corner of your screen
2.At the bottom of your screen you should see a tab labeled “Excel Options”. Click on that tab.
3.In the list of options on the left of the screen, click on “Add Ins”.
4.Look for the box labeled “Manage”.
5.In the box you might see one or more file names. Click on each one you want to enable, then click on the “Go” button. You might have to select the file names one at a time followed by clicking “Go”. The selected file names should disappear from the list, indicating they are now enabled. If there aren’t any names in the list, then none of your files have been marked disabled.

You can read this in the Microsoft Knowledge Base by going to:
Support.Microsoft.com/kb/286017

HTH, Sid