I installed Administrator on win7 PC and can do it from there, but eventually and quite soon win7 will be discontinued like XP... and then....
Then you take the myisamchk.exe (if your DB is MyISAM) and do whatever MySQL Admin did in the GUI from the commandline.
Or you could just take mysql.exe and run a REPAIR TABLE <insert-name-here>; query.
If your database is using the InnoDB engine, though, there's nothing myisamchk or MySQL Administrator could do for you. InnoDB is self-healing. Just stop the MySQL daemon and start it again. If that doesn't help, the indexes might be broken, but can be rebuilt as well. Check out the link in my last post.