I have been running a PCLinuxOS 64-bit test system for some time. A recent update has messed up the startup in so far as KDE4 will not come up. I can boot up on a LiveCD and can edit files but cannot access the original system because I when I try, it tells me "kdeinit4 is inaccessible, please check your installation'. When I press 'OK' it takes me back to the message once more. Is there a solution?

Please verify that all packages were updated successfully.

As I cannot get in, I cannot gain access to the repository!

You should be able to login on the command line, by switching to a virtual terminal. Unfortunately, I am not familiar with PCLinuxOS' package manager.

Have you tried a failsafe KDE login to see if that works on the off chance?

First of all I will suggest (if you haven't already) that you ask for assistance over in the PCLinuxOS forum where you will get more distro-specific help in fixing your problems. The people over there are very responsive and very helpful.

You have a couple of options for getting into a working environment, assuming the system fully loads up sufficiently to get to the login screen. First, on the login screen there should be a button usually labeled Sessions or some similar which can be used to select which desktop environment to log into with options such as KDE, failsafe, and possibly gnome, fluxbox, openbox, XFCE, enlightenment (16 or 17) if you have previously installed them. The failsafe option opens a bare-bones environment with a terminal you can use to issue commands (like using "su" with the root password to switch to the root user and launching synaptic to re-update/re-install any mangled updates and installing a less bare-bones fall-back environment like fluxbox or openbox for such occasions as this). You can also start KDE from the terminal and examine any errors that it prints out with the startkde command.
The second option is you can ditch the graphical environment altogether by switching to a virtual terminal with ctrl+alt+f1 (use ctrl+alt+f7 or f8 to switch back to the graphical environment). There you can log in and issue commands just like in the failsafe environment, except that you can't launch graphical applications like synaptic. You can use apt-get to perform the same operations as you would in synaptic; use "apt-get update" to resync the package list with the repositories "apt-get reinstall package-name" to reinstall packages, "apt-get dist-upgrade" (not "apt-get upgrade" which is not supported on PCLinuxOS) to install any available updates, and "apt-cache search package-name" to look up what packages are available.

I couldn't wait and chose the easy way out. I reinstalled the OS from the install CD. It didn't take too long to restore my personalisations. Thanks for trying to help. This is not really satisfactory. I prefer to complete repairs in a more professional way but I had work to do and deadline to meet. I'll try to prepare for a similar scenario as soon as I get some time.

Kind regards

Alan