Somewhere on my computer, details of my email address, home address etc are stored and I have no idea how to access it. For example I changed my email address last year and when I try to log into websites, I am presented with both my current email addresses and old one - where are they stored, as I don't know where to go and deleted the obsolete email address?

When I register a new programme, my computer automatically shows my name as 'Comet' (this is actually the store where I bought the computer) how can I find where this is stored so I can actually put my name?

Any help would be gratefully received.