AppCrashView is a simple tool that displays the details of every program crash you've experienced recently.
Just seeing the list can be informative. Knowing that Explorer.exe occasionally crashes on your PC is one thing. Having a list that shows you this has happened 25 times (or whatever) in the last week, while also listing the time of the crash, the user involved and other information is much more useful, clearly highlighting what's going on and maybe offering clues as to the cause.
You may also discover problems you didn't know existed. On our test PC, for instance, we found reports of a "service hang", a third-party Windows service that had locked up on starting and was slowing our boot process down. No error message was displayed, so if something similar is happening to you then you may not know about it. View the issue in AppCrashView, though, and you could reinstall or update the relevant application and quickly get your PC back to normal.
You get details on exactly why the crash has occurred. It turned out our test system's IE8 crash reports included some that occurred because of a "webpage display problem", for example: could these be fixed by using IE8's Compatibility Mode?
And what you'll also see is the "fault module name", the name of the file where the crash occurred. Enter this at Google along with a key word like "crash" and you'll probably find similar reports from others, perhaps with fixes that will restore your system's stability.