I cannot enter the dashboard in twenty eleven

Sorry for the stupid question. My site is still on my localhost and almost ready for uploading. But I accidentally changed the site’s address in the dashboard. And now I cannot enter the dashboard. WordPress offers me to enter password under Admin. I think it was Admin, as well. But WordPress claims the password is not correct. What can I do? I wouldn’t like to reinstall WordPress and loose all my data. On the face of it, the folder with all the files and pages still exists, of course. I can copy it to some other place. Is there any file where I can manually correct my site address in the dashboard? Thanks a lot