I had the good experience of removing local domain account (windows authenticated user) from my mssql database and you guess it, i was not able to login at all using windows authenticated users.
Instead of reinstall my database, here's what i did :-
a) stop "Sql Server (MSSQL Server service)
b) net start mssqlserver /m
c) fire up SQL Management studio and login using Windows Authentication.
d) Perform recovery process whereby you add relevant users accounts here.
e) Restart your MSSQL server service and login.