His career just got derailed. Who's gonna hire a guy who presided over the biggest disaster ever at his previous company?

HP?

That's a good point. Maybe it would be more feasible to have the server cache the current password in RAM during the mandatory password change process, so it can at least compute edit distance from the previous password.

Or for added fun, have a server dedicated to brute force password cracking. When it gets somebody's password, their account gets flagged for a mandatory password change.

OMFG! Our universe is going to puff out like a fart in a car in tens of billions of years!

Well when I fart in my car, that sucker doesn't go anywhere until you force it out, so I wouldn't be too worried then.

I find that a decent SQL database platform is better for complex data manipulation. Install SQL Server 2012 Express Edition With Advanced Services (it's a mouthful, but it's free). It supports import/export from Excel spreadsheets, and a number of other data formats, and also includes Reporting Services for creating nice presentable reports without coupling the layout with your data storage (as with a spreadsheet).

Some SQL knowledge can take you a lot further than Excel will on its own.

...or give up having any wall space not covered by books.

And you view this as some sort of problem?