OS bolloxed after latest update

Sorry for lack of detail - what happened was that I installed the latest software updates from Apple, and also "tried" to install the latest Java but that install was unsuccessful according to an error message. After rebooting the system, I was able to open Opera fine from the dock, but when I tried to open TextEdit the icon bounced a bit, the arrow appeared below it, but then the arrow faded away and no program open. I opened Force Quit to see if it was running in the background, not there. Tried opening System Preferences icon from the dock, same result. Can't open it from the Apple menu either. I also notice the clock and other icons (keyboard language etc.) only appear intermittently in the menu bar at the top right corner. Yet I can open certain programs such as TextWrangler from the Applications folder and they work fine, I can also open Finder windows.

I'm going to reboot again and test tonight when I get home, then maybe try your steps if nothing else works. Luckily most of my files are backed up on my external HDD or on web servers anyway.

Thanks!

Here's what happened. I was unable to do the archive install, at the very end after over an hour I got a message that there were errors on the disk. So I used Disk Utility, ran Verify and got tons of errors about catalogue files. Tried Repair and got a message that it couldn't repair the problems. Then I tried (last resort) Verify Disk Permissions and again got a load of errors. Tried Repair Disk Permissions and it couldn't repair. Tried install again "error occurred during installation, please try again" right at the end of the installation. I tried two more times, same error and Disk Utility was still seeing problems with the disk. So I figured it was a HDD issue (this mac is 4 years old) and replaced the hard disk.

Before, it had a 40 GB drive, I installed a brand spanking new Seagate 80 GB so I'm not sure if the size could be causing this issue. I formatted it with one partition using Disk Utility, Mac OS, journaled, system sees it fine and Verify tells me there's nothing wrong with the disk. So I run the Installer, it tells me during drive selection that this volume cannot have OSX installed on it. So, I reboot, same problem.

Then I read the Read Me of the Installer and find that it likes the first partition to be less than 8 GB. News to me, since I was able to nuke and reinstall on my old 40 GB drive before without a second partition. Anyway, I repartition the drive with one 8 GB partition and the second containing the rest of the disk. Installer now tells me I can install on either partition, I choose the first one. An hour later at the end of the installation "error occurred during installation, please try again". Now I'm trying on the larger partition but not holding my breath for any success.

I'm wondering if I have a bad install disk? I can't eject the bloody thing because now the hard disk isn't bootable and it automatically boots to the disk. I tried booting to the firmware after doing some googling, doesn't work if the HDD isn't bootable I guess. I can't restart because Installer doesn't give that option, so holding the mouse button during restart isn't an option. All I can do is power it off and on with the power button. The Eject button on the keyboard was the first thing I tried.

Any other ideas? I do have a second unopened copy of all of my install disks that was given to me by the store when I bought this thing. Or should I just pitch it off of my balcony as I've been sorely tempted to do?

I finally managed to boot to the firmware (was like playing Twister with your fingers on the keyboard, having to hold down 4 buttons which weren't near each other) and eject the OSX disk #1. I then ran the hardware test, and found there's a memory error. I ran the extended test twice with peripherals removed just to be sure. I just upgraded my RAM to a GB last year, so I'm a bit miffed. Anyway, I guess I'll be going out to buy some RAM now and see what happens from there.