Problem accessing the Market I have a Sony Ericsson Xperia with Android. I can't download from the Market because there is some Gmail account that I don't have an idea how it got there. 

This means that I don't know the password! I have tried to change that email but I can't so what is your suggestion what should I do?
Go to Settings &gt; Accounts and Settings, click on the account that you don't know the password and then click the Remove Account button on the bottom. So next time you open up Android Market you'll be prompted to type in a new account