Hi
1) Remove every file from your XlStart folder
C:\Documents and Settings\Ron\Application Data\Microsoft\Excel\XLSTART
In Vista look here
C:\Users\Ron\AppData\Roaming\Microsoft\Excel\XLSTART
Note: Ron is the username in the path above
2) Uncheck every add-in in the add-in list
Click the Microsoft Office button, click Excel Options, click the Add-Ins tab.
In the Manage drop-down, click Excel Add-ins, and click Go.
Uncheck them all
Start Excel normal
If it is working OK
Add the workbooks/add-ins one at the time until you find the bad one