Thank you, MetalJ - the link is very helpful!
Windows Error Reporting - (Vista only) Whenever a program crashes, Windows saves details of the crash to report back to Microsoft. This option will clean all the error reports from your system."
I will leave the box unticked. Sometimes I will get a "fix" back from Microsoft immediately, on a crash that automatically reports to them. Often, however, there is no fix available at the time, but Microsoft periodically revisits old crashes to see if a new fix has been created to solve the problem.