Lost admin name/password

WP is not accepting my admin/password. I know the password, but maybe not the login name. What was the default admin name for 1.5? This probably was what I used.

Background: I had a major meltdown — had to rebuild my main box plus maybe am short a brain cell or two. Now I can’t get in. I’ll re-build from scratch if necessary, but would prefer to preserve my minimal blog.