WhoCrashed is a utility that you can use to help find out what is causing full system crashes IE: Blue Screen of Death or the computer just shutting off all together.
It will not help you find out why a game or program is freezing, lagging, crashing, or anything of the sort.
This is very straightforward, you open the program and click Analyze
It will then instruct you to scroll down and read the Analysis and Conclusion. If what it tells you does not make sense to you, simply post it on the forums for help or submit it to Main Performance PC with a support ticket directly here in our Help Center.
If you do understand it and are working on it on your own, keep a word document with saved results so that you can track different problems and solutions.
Its very common to see driver problems here. If a driver is named, make sure you are using the most current version of that driver by searching for it with Google.