Mac Forum / Applications / Mac Applications / January 2007

There's no harm in running "repair permissions" but it's much like
rebuilding the desktop in OS 9 and earlier, unlikely to fix the problem
you think you're trying to fix.

It should work. Is it the original disk that came with the Mac, or a
full retail version?

What happens, exactly?

What happens if you hold Option instead of C? Can you select the CD/DVD?

I don't know which one you were told, but neither is correct. If you use
verify it will tell you if anything appears to deviate from what it
should be. If you use repair it will attempt to correct any deviations
and report those attempts along the way..

I'm not sure if that's still supported on all machines. The preferred
technique to select the boot drive during system start is to hold down
option (starting right around when you hear the chime). You will be
presented, eventually, with a display of all found bootable devices. At
this point, the optical drive can be manipulated and there's a button on
the screen to rescan if necessary.

Neither.

Here's how it works:

If you press Verify Permissions, then Disk Utility will scan the disk
looking for permission errors and will give you a list of them, but it
will not fix them. If the permissions are screwed up when you start,
they will be screwed up when you finish. "Verify" in this context is a
verb meaning "show me what you would fix if you were told to fix things,
but do not actually fix anything."

If you press "repair permissions," then Disk Utility will look for
permissions that are out of whack, and fix them.

I find "verify permissions" to be a complete waste of time. If you find
permission errors, you want to fix them, so after you hit Verify you'd
most likely just end up hitting Repair anyway.

Which universe are you trying to prevent from exploding here? What
problem are you trying to fix?

Are you holding down the C key at the right time, and for long enough?

To be certain, hold it down from the moment you hear the startup chime,
and keep holding it down until you see the Apple logo from Mac OS X (or
the Happy Mac icon on older versions).

Another possible explanation is if your computer has been set up with an
Open Firmware password, to restrict access to Open Firmware. This also
stops you using the 'C' key to boot a CD, and the Option key to select a
startup disk.

Yet another possible explanation is that the CD isn't bootable or
readable by your computer. Are you able to boot from that CD by using
Startup Disk in System Preferences to select the CD as the startup disk?

Hei Doug

Verification will only tell you which files if any are out of order. A
direct presure on 'Repair Permissions' run first through a verification,
then a repair. NONE of them will make any harm to your data, system or
files...

Are you using a DVD in a CD drive - fx. a Tiger install disk on a
computer, which hasn't a DVD drive but only a CD drive?

Have you replaced the original CD or DVD read only drive with a burner?
Some drives won't work in some models. - I had the boot problem some
weeks ago with a LiteOn LightScribe drive that wasn't bootalbe on my
QuickSilver. - no firmware update worked out this problem, so I had to
deliever it back to the store and wait until I got an original
SuperDrive - a Pioneer DVR-127D from OWC. This one worked right out of
the box... So this might be your problem...

cheers, Erik Richard

[...]

c is.

There can be good reasons to not Repair Permissions, but only for those
who understand those reasons, as there are implications. Those who don't
understand the implications are better served doing what Apple offers
and suggests: run Repair Permissions when your Mac seems to have a
problem.

Applies only to internal drives AFAIK.

Alternatively, you can instead hold the Option (= Alt) key, to get a
menu that allows you to select from all find bootable volumes.

For all such 'startup keys' applies that if the keyboard isn't yet
recognised at that point,pressing its keys obviously won't have any
effect. So it may be that these things don't work for certain
third-party keyboards, and for BlueTooth keyboards.