“<Some program on Windows> has stopped working”

Question

I have been running mercurial (on Windows) for many months and I am suddenly now getting the error "Mercurial Distributed SCM has stopped working" in a Windows dialog. I can't find anything by searching on the web. Is this a question of reinstalling or is it more fundamental?

EDIT: Because of the helpful answer indicating that this is a Windows problem I have changed the title

Answer 1

This can be more fundamental that just a reinstall, and it can happen for all sort of programs (not limited to "Mercurial Distributed SCM")

This article explains that, if a reinstall isn't enough:

If for some reason you still can't get ride of this error, we recommend you to download the most popular registry repair tool, Registry Easy to fix this error