I found a great plea from Soma, a Microsoft developer, on his blog Shipping Seven. It's a bit old but very relevant - I felt you should all see it so I am reprinting it here:
Do you hit the same annoying Windows Vista crashing bug day after day?
Please, please, please click the 'Send information' button when you see this crash dialog.
If in the very unlikely event that you are the first person to encounter and report this bug, a new entry in our bug database is entered automatically.
If anybody else encounters the same bug, and reports it, our automated crash reporting system finds the correct bug in our database, and then updates a counter. (Basically, there is a field in the bug that indicates that X people on the internet have encountered this bug.)
If you don't report the crash, that counter is not updated.
Why is that important?
Our ship room (a bunch of guys who decide which bugs should get fixed and added to SP1, and which bugs are too minor to be fixed) rely a lot on this counter. If the counter reaches more than [redacted], we fix it.
So, every time you encounter any crash - hit that 'Send information' button. Please.