If your bootloader gets changed or corrupted, this fix will restore it without damage to your disk partitions.

This hint may be a bit esoteric, but I thought I was up for a long night of reinstallation pain before stumbling upon this fix. I made the mistake of trying to use an Ubuntu 9.04 boot CD to install Ubuntu to an external (USB) drive on my Mac.

Don't do this, unless you know the following: Regardless of the fact that you chose the external drive upon which to install Ubuntu, you won't be able to boot back into your Mac without changing the bootloader. I ended up with the dreaded question mark folder when I tried to reboot my Mac, and nothing worked to boot into my OS X partition.

Luckily, I have a bootable external drive with OS X on it, and I was able to boot into it by holding down the Option key (the primary partition still did not show up).

Over the weekend, in preparation for an upcoming review of the newest versions of Fusion and VirtualBox, I needed to set up a new Boot Camp partition on my MacBook Pro. Because Windows 7 isn't yet officially supported by Apple, and Vista isn't widely used, I chose to install XP Pro. My XP Pro disc is a Service Pack 2 release, so after booting into Windows, the system found and downloaded a bunch of updates to apply, chief among them Service Pack 3 (SP3).

The update process went smoothly, until the system tried to install SP3. The update process started, then died with this error:

An error occured while copying file osloader.ntd. Cannot copy file to destination directory. Click Retry to retry the operation or click Cancel.

At that point, the only solution was to bail on the update, and have Windows back out the changes it had already made. I tried a few times, but always got stuck at the same point. After a fair bit of digging and hair pulling, I found this Apple Support document that describes the problem, its cause, and (most importantly) the solution.

You can read the details in the support doc, but in case that ever vanishes, here's a quick recap. The problem is caused by Windows' insistence on writing the SP3 update to the first partition it sees. Because Boot Camp 3 mounts your Mac OS disk as a read-only disk in Windows, this is the first partition the system sees, and the SP3 install fails.

While attempting to upgrade my MacBook Pro to 10.6, I received the error message "this disk cannot be used to start up your computer." I only have one disk and one volume, so that disk was my only choice.

I tried running Disk Utility to repair the drive, but that didn't help. I searched the web and came up with a solution that works. Using Disk Utility from the installer, slightly reduce the partition size on the boot disk. The act of changing and rewriting the partition seems to fix whatever is causing the issue.

In Leopard, Software Update gave you the choice of either downloading or installing an update. Under Snow Leopard, though, the download option is gone; it's install or nothing.

[robg adds: There's a new Update » Go to Apple Download Page menu item in Software Update; every update should be available there for download. While this change simplifies the Software Update app, it does add a step for those who prefer to download updates (for updating multiple Macs, for instance).]

My Logitech mouse stopped being recognized in Snow Leopard. Logitech, in their infinite wisdom, has their Logitech Control Center 3.0 installer recognize and defeat any attempt at installing on any system other than 10.5.

The simple solution is to view the contents of the installer .pkg file (Control-click on it an select Show Package Contents), then navigate to Resources » Logitech Control Center.mpkg and double click. This launches the installer with no system version test, and re-installs the components in the correct locations. Restart and voilá -- mouse recognized!

[robg adds: I don't have a Logitech mouse to test this one with.]

After installing Snow Leopard, all my menu bar icons disappeared. After some digging, I found out that version 1.3 of iStat Menus is not compatible with Snow Leopard (version 2.0, released shortly after Snow Leopard shipped, is compatible).

I had a problem, though, because the uninstaller is located within the iStat Menus System Preferences panel. Since the panel would crash every time I tried to open it in Snow Leopard, here's how I solved that problem. First, I downloaded the 1.3 installer from the web site, Control-clicked on the package and chose Show Package Contents from the contextual menu, and found the uninstaller tool in the Contents » Resources folder. As soon as I had this uninstalled, my menulets returned.

So make sure you upgrade to version 2.0 (assuming you're running 10.5) prior to upgrading to Snow Leopard. Alternatively, uninstall iStat Menus 1.3 before upgrading.

[robg adds: I modified this hint quite a bit, as it was submitted prior to the release of iStat Menus 2.0.]

One of Snow Leopard's many refinements is QuickTime X, which comes with a new, simplified version of QuickTime Player. The new player focuses on elegantly displaying video, but loses most of the editing capabilities that have been a core feature of QuickTime since 1991. The new version doesn't even have a Preferences window, and you'll notice that the QuickTime pane in System Preferences is gone too.

Fortunately, QuickTime Player 7 still works. In fact, the old version of the player (7.6.3) is a custom install option, and is also available as part of the Optional Installs package. The description says "for use with older media formats," begging the question of what else QuickTime X doesn't do. On the bright side, you don't need a QuickTime Pro key any more to take advantage of the editing features in QuickTime Player 7 (more value for your $29).

QuickTime Player 7 has the option of blacking out additional displays when playing a movie full screen. QuickTime Player X annoyingly doesn't have this option, which is quite distracting when trying to enjoy a movie without your work getting in the way. Here's a workaround if you have a Cinema Display: in Display Preferences, under options, you can program the display's power button to turn the display off. Voila, a black screen. I suppose if you have any other display you could just turn it off the normal way.

Comments on what other features from QuickTime Player 7 you wish were included in QuickTime Player X? Maybe eventually it'll grow a Preferences window again.

If you're like me and you need accessibility options, then you know that the install disc (this hint works with both the 10.5 and 10.6 installers) poses many problems. Fortunately, there's a work around for that tiny 12 point font in Terminal.

When you open the Terminal app from the Install Disc, you can't access Preferences. Go to the Shell menu and click Show Inspector, or use Command-I. Now click the Settings tab. Double-click on any of the view options. This will change the window and bring up preferences in the background. I use the Homebrew settings, but with a 24 point font (normally, it's 20 and I use Universal Access.). Then I can click on the Change Font button and it works just fine. You have access to the other settings as well.

Note that I wouldn't change every setting, because they won't be saved the next time you use the installer.

I just installed 10.6 over 10.5, and when I restarted the final time, a window came up right after login asking for me to locate system events.app.

I called Apple Support, and their advice was just to hit Cancel. The window doesn't come back on future reboots, but this does seem to happen once for each account on the machine.

Just wanted to share that it seems to be safe to cancel it.

[robg adds: I haven't seen this on any of the four Macs I've upgraded here; not sure what might trigger the event.]

Clojure is a hot new programming language on the Java platform that's getting lots of attention lately, but setting up a development environment on OS X can be a bit of a pain.

To make things simpler, I created ClojureX, a free set of scripts and installation instructions for this task. ClojureX can:

• Download and build the source code for Clojure, clojure-contrib and JLine (a readline like library for Java)
• Download editor support packages for TextMate and Emacs
• Create a symlink for the Clojure startup script in /usr/local/bin
• Install support for TextMate via the clojure-tmbundle
• Configure Emacs to use clojure-mode, Slime and swank-clojure
• Keep your Clojure installation up to date via a simple git submodule update && ant

More info can be found in this blog post.

[robg adds: Just in case the source ever vanishes, I've created a mirror on Mac OS X Hints. However, your best bet for the latest and greatest is via the link to the tree on github.]