This same problem has happened to me twice in the past. I don't know what happens, but all of the sudden my KDE decides to break and freeze while starting up. My icons all load, but while one of the startup programs is loading, compositing breaks and everything freezes. As far as I know, nothing I did caused this. I booted into KDE accidentally, so I restarted into Windows. Later on, restarting back into KDE, it freezes.

Any way to fix this? Or can I just reinstall KDE somehow? Or what should I do?

Thanks!

It appears that some application causes KWin to use a compositing extension that is not properly implemented in the graphics drivers on your system. This application very likely only loads under certain conditions ( Akonadi perhaps )

You can disable KWin compositing from a terminal. Simply edit the file $KDEHOME/share/config/kwinrc. Find the section "[Compositing]" then change the line "Enabled" to false. You should then be able to login.

Are you running Kubuntu 9.04? I remember that last week or so there was an X update that broke KDE/Gnome when compositing was used, but an update pushed out a day or so later fixed that. If you're running 9.04 I'd recommend updating.

hi dude if you are using the solaris you can solve it very easily using dtrace (its a tool in solaris).Generally this can be solved if you decrease the number of processes that are being loaded in the memory during startup.even then if the problem is present the check your mother board (mainly for graphic problems).