Emac won't get to sign in screen

Question

Hi, I can't sign on to computer. I put in install disc and ran repair disk and one repair was listed: invalid leaf record count. (It should be 26 instead of 17) That was the last thing I tried. Earlier I started the computer holding dow Shift-Command-V and after all the text mumbo jumbo appeared the last this it said was...unable to find default windowserver or something like that. Now I've lost the piece of paper I wrote that down on. This all started after I did a security update that came up on a usual software update check. Also the screen used to show the grey screen, apple logo, and the little turning gear,...now it only show the grey screen and apple logo. I can't tell you what system I have because I can't use the computer to find out, but I think it was around 10.4.?? I'm not very good at computers I hope someone can help. Before the message above about the windowsever? I was trying to initialize a signon application or something like that. Thanks anyway, Marilyn

Answer 1

What might have happened is your computer was having minor problems before you did the update. Then the update couldn't install something correctly and this has magnified the issue, leaving you with a broken operating system. It may have something to do with the directory error you are seeing in Disk Utility.
The standard procedure at this stage is not to do anything else until you have a repaired directory. Two ways to go here.
One is to erase your hard drive and reinstall everything new. This erases all data so not many find it an attractive route, especially if you have not been backing up your data. Now you still haven't told us if you can boot to safe mode, and that may influence how you proceed if you go this route. If you can boot then you can back up your data (always bearing in mind that some may be corrupt due to the broken directory). Then you can install the operating system again and re-install everything and replace your data. If you can't boot to safe mode then maybe you can install the operating system on a bootable external drive and do it that way, or rescue your data via target disk mode. I won't go into details of each of those methods until you have told us if you can boot to safe mode, if you have a firewire external drive available, or a second Mac computer.
The other route to take is to buy Diskwarrior (ca. US$90) which is probably the best tool at repairing directories. Assuming it can repair the directory you can then go about trying to reinstall the update, or do an archive and install of the operating system which leaves your data and settings intact. You don't want to do an A&I with a broken directory though.
For future reference, here's what I do with updates:
Updating
Certain steps appear to minimize the risk of an update producing problems.
Number one is to make sure you have a bootable clone backup of your computer in case you do need to back out of it again. This is the only guaranteed way of not having to worry about the results of an update.
Some like to boot from their installer discs or an external backup and verify (and if necessary repair) their internal drives as well as drive permissions. This is done with Disk Utility. You can verify a drive while booted from the same drive but sometimes this produces spurious errors. Repairing a drive (if necessary) has to be done while booted from another disk. Permissions repair can, and is probably best, done when booted from your internal drive.
[Resolve startup issues and perform disk maintenance with Disk Utility and fsck|http://docs.info.apple.com/article.html?artnum=106214]
[Using Disk Utility in Mac OS X 10.4.3 or later|http://docs.info.apple.com/article.html?artnum=302672]
[Disk Utility's Repair Disk Permissions|http://docs.info.apple.com/article.html?artnum=25751]
You can also go to the step of booting into safe mode to do the install.
[Mac OS X: Starting up in Safe Mode|http://docs.info.apple.com/article.html?artnum=107393]
[What is Safe Boot, Safe Mode? (Mac OS X)|http://docs.info.apple.com/article.html?artnum=107392]
[Safe Boot takes longer than normal startup|http://docs.info.apple.com/article.html?artnum=107394]
I like to download the update onto my computer and install it from there rather than let Software Update do it. I know a few people who had problems with doing the update via software updater found a manual install to work.
Repair permissions again afterward.
It helps to only install one update at a time and to run the computer for a while to make sure it is behaving well.
The more cautious even like to unplug third party peripherals (see [comment by BDaqua|http://discussions.apple.com/message.jspa?messageID=9040746#9040746]).
Almost all of the above steps (except backup) have been questioned as to necessity because probably many people have done successful updates without doing them. I say they can't hurt, they can very likely do good (especially if your computer isn't regularly maintained), so why not do them to be safe.
[BDaqua's comments on updating problems|http://discussions.apple.com/message.jspa?messageID=8948595#8948595]
[Baby Boomer's comments on updating problems|http://discussions.apple.com/message.jspa?messageID=9025760#9025760]