I repeatedly encountered the following error message in Windows 7 x64 Ultimate:
The version in question was Microsoft Excel 2010. Excel was working fine on my machine (a Lenovo E430 ThinkPad); this was happening only when I ran Beyond Compare. When Beyond Compare was comparing the contents of the laptop’s internal hard disk drive (HDD) against the contents of an internal 3.5″ HDD mounted in an external USB drive bay, it flashed that message repeatedly. It seemed to happen only when Beyond Compare found a difference between copies of Excel spreadsheet files on the two drives. I was not getting this problem on a similarly configured Acer laptop — only on the ThinkPad.
A search specific to Beyond Compare turned up nothing, but a more general search revealed that people encountered this error in a variety of settings. For example, a Spiceworks webpage said the problem could be caused by ABBYY FineReader OCR software, installed with Epson printers and scanners. I did not have ABBYY or any Epson software installed.
Some discussions suggested disabling COM add-ins. To do this, in Excel I went to File > Options > Add-ins > Manage > COM Add-ins. In my case, that helped: I unchecked the COM Add-ins shown there, revised and saved an Excel spreadsheet, re-ran the Beyond Compare comparison, and this time the “Microsoft Excel has stopped working” error did not appear. Further investigation suggested that, at least for me, the problem might be related particularly to the Tabs for Excel v7.00 (32-bit) add-in; unchecking the box next to that one was the specific fix. I wasn’t sure where I had gotten that add-in, but a search led to the different and hopefully better Detong Office Tabs 9.50.