Repairing startup-disc/ maintenance

[dadgadder]

This is the message I get when I run Onyx maintenance "The volume needs to be repaired. To repair your startup-disk, start up from your Mac OS X Install disc (CD or DVD), then choose Utilities> Disk Utility...
is this the original install disc or would it be the latest disc I've installed (Tiger 10.4.6 now updated to 10.4.8)
then when I optimize the system I get this "Error detected while optimizing System" The command exited with a non-zero status.
I'm having some problems with the computer which are probably related to these messages. I have the current version of Onyx.

[DeltaMac]

Yes, start from your 10.4.6 installer DVD, and run the Disk Utility from the Utilities menu. you'll be able to run the repair.
Keep in mind that you may have problems on the drive that Disk Utility might not successfully repair, and then you should try another, more powerful utility such as Disk Warrior. You may even find that you can't repair the disk, and it's rapidly time to back up all your files, and erase the disk completely, or even replace the hard drive.

[Satcomer]

BackUp, BackUp, BackUp!!! i can not stress this enough. Hard Drive fail, that is fact. Most Hard Drive fails are like old style Hollywood cartoon deaths. The gasp for ages then dye. By your description your hard drive is starting to gasp. BackUp now and replace that drive before the drive completely fails.