Sounds like you need to do a bit of house keeping on your pc first.
Go to http://www.ccleaner.com and download their free app.
clears out old rubbish and there's a registry checker.
Run a disk cleanup through Windows disk management too.
Then reboot and see if your machine is still stable.
Google your iTouch/blue screen issue.
Maybe your anti-virus need an update, or you need to kill off some uneccessary startup programs.
Did you change anti-virus programs recently?
Next time it blue screens (if it does), write down the error codes and google them as well.
Good luck!