Linux Programs are (afaik) launched with a command. Try hitting alt+F2 or
opening a terminal and typing in the name of the program. That will often
be all you need. Once you find the command, it is pretty easy to make a
shortcut for it on the desktop or put an entry in your start menu. Also,
things often get added to weird places in the start menu, so you may want to
check unexpected places (i.e., everywhere) if you have not already.

If you're still having problems after trying the above, post back with the
name of the program.

Alien is a command line only program, I'm afraid; for this reason, it's
not placed in the applications menu.

Open up a terminal, cd to where you have the .rpm (presumably you're
wanting to convert from an .rpm to a .deb) and type in "alien
" (obviously, without the quotes and changing
appropriately :-) ) and you should, if all goes well, get a .deb ready
for installing.

For more information, type "man alien" for the manpage (q exits).

I just installed it and in a terminal executed it and got the command
help printed out. I then entered the command "locate alien" and got the
response here.
/usr/share/app-install/desktop/alien-arena.desktop
/usr/share/app-install/desktop/alienblaster.desktop
/usr/share/app-install/icons/alien-arena.png

I hope this helps, or you could use synaptic to remove it and then
reinstall it, then in terminal window enter the command like I did.

Thanks I did what you suggested found in Terminal,but cant find it
anywhere?

That is a game not alien, the commandline tool.

Follow this guide.
www.howtoforge.com/converting_rpm_to_deb_with_alien

Type in the terminal

alien-arena

Arena is a game and not a file converter! I know i've just
installed it !