The MySQL service is starting... The MySQL service could not be started. A system error has occurred. System error 1067 has occurred. The process terminated unexpectedly.
Very descriptive. Thanks. I tried checking for a log file from MySQL, but could't find it. Strange. Well, it turns out, MySQL on windows has its data directory at C:\ProgramData\MySQL\MySQL Server 5.5\data. You can verify this in your installation by looking at the my.ini file, in your MySQL installation directory (probably C:\Program Files (x86)\MySQL\MySQL Server 5.5\), and finding the line that says datadir=...
I didn't even know ProgramData existed! It's hidden, so either unhide it (Control Panel -> Folder Options -> Show hidden...) or simply enter c:\ProgramData into your explorer title bar. In this data directory, there should exist the log file [hostname].err. Taking a glance at that, I found:
InnoDB: Error: log file .\ib_logfile0 is of different size 0 33554432 bytes InnoDB: than specified in the .cnf file 0 56623104 bytes!
Thanks to this post on forums.mysql.com, I found that simply deleting ib_logfile0 and ib_logfile1 solved the problem. Seems like a dumb installer mistake to me! A bug report already exists, so I'll just keep quiet until the next install :-) Hope this helps!