One Mac utility that has maintained its incredible quality for many years, through many different revisions of the Mac OS, is Alsoft’s DiskWarrior 4. And I want to give them a big plug right now, because once again DiskWarrior has resurrected a startup disk that lost its startup.

This morning I was browsing some Mac sites and saw that Adobe had released a new version of their Flash Player, to address a list of security issues that had been known for quite some time. So I downloaded the installer, quit all my browsers and other apps, installed the new version, then cranked up Safari 5 to make sure everything was still fine.

Everything was not still fine. Flash videos weren’t appearing all the time. Sometimes they’d show up, other times they wouldn’t. Worse, I started having other weird display problems in Safari; flickering dialog boxes, symptoms I had never seen before. Good work, Adobe.

I decided to restart in Safe Boot mode, by holding the Shift key during startup. This clears all the caches, does some other housekeeping, and runs the Unix fsck utility to find and repair any disk problems. Or it’s supposed to, anyway; in this case, it got about a quarter of the way through and hung up. I waited over an hour to make sure, because an fsck on a 1TB disk can take quite a while, but that thermometer bar was not budging.

I forced a shutdown (by holding down the power button for five seconds), then restarted in Safe Boot mode again. Same thing happened. Argh. More drastic measures were obviously required.

Fortunately, I have a bootable image backup that’s automatically updated every night, via the excellent SuperDuper backup program. So I restarted the computer again, this time holding down the Option key to display the list of bootable drives, and picked the backup, which started up right away.

This is where DiskWarrior came in; whenever I have a problem like this, that can’t be fixed via Safe Boot mode, the next step is to try DiskWarrior. I rarely have to try anything else.

DiskWarrior works by analyzing a disk’s complete directory, and building an optimized replacement directory that is verified and then written to the damaged disk, and I’ve seen it bring some disks back to life that seemed like total goners. And it came through again this time; after rebuilding and replacing the directory, I restarted again and everything worked right away.

A little bit faster, in fact, since the new directory is nicely optimized too. I heartily recommend DiskWarrior for all Mac users; it’s one utility you absolutely must have, for those inevitable hard disk problems that plague us all.

P.S. I don’t know for sure that installing the latest Mac Flash Player caused all these problems, but my system went south immediately afterward. If you want to install it (and I’d recommend it, since it fixes some serious security holes), make sure you have a backup first.

P.P.S. After running DiskWarrior, my system works fine even with the new Flash Player, so the player isn’t the cause; possibly the installer.

P.P.P.S. I take back what I said about the new Flash Player working fine. I suddenly began getting psychedelic screen displays in Safari. The screen was all jumbled up like a jigsaw puzzle. Whee!

I just ran the Flash uninstaller, and reinstalled the previous version. (I wish I didn’t still have to use Flash player. This is one of the suckiest pieces of software in wide distribution.)