You should run: "sudo /sbin/SuSEconfig" if you aborted suddenly. Shutting the power down suddenly is always a bad idea for any OS. You can use the ps command to identify the process running.
If a program is hung, use the kill command.
It's also possible that you have used up your resources. This will make the computer seem to stall.
Also, reduce all windows one at a time. There may be a modal dialog which you need to close.
If it still won't quit, try '[ctrl]-[alt]-F2' and log in as root. Then enter "shutdown -r now".