How do you open unreal development kit?

Once you have the program installed, go to the Binaries directory:

example: c:\UDK\UDK-2011-03\Binaries

1) Find the UDKLift.exe

2) Create a desktop shortcut for the UDKLift.exe

3) Right click on the desktop shortcut and click properties

4) On the target line, after the UDKLift.exe write editor. The target line should be similar to this (your drive:\installed directory\binaries\):

C:\UDK\UDK-2011-03\Binaries\UDKLift.exe editor

5) Apply settings and you should be in business once you click the desktop shortcut.