When you install games for KDE in Ubuntu (Gnome) and then you search for a guidelines in the game help, you will get “Could not find service ‘khelpcenter’”. Because, you don’t have KDE Help Center in your gnome. This program have to be installed separately.
The installation is very easy.
taufanlubis@toshiba:~$ sudo apt-get install khelpcenter
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 2318kB of archives.
After unpacking 4080kB of additional disk space will be used.