Don’t know why NetBeans not has an option to choose the user interface language, it use the Windows system language as the default.

It took me a while to figure out how to change the interface language.

1. Temporary Solution

Add "--locale en:US" at the end of Netbeans startup command. 

"C:\\Program Files\NetBeans 7.1.1\bin\netbeans.exe"  --locale en:US 

2. Permanent Solution

Go to Netbeans installation directory, for example,

C:\\Program Files\7.1.1\etc

Open “netbeans.conf” and find netbeans default option line

netbeans_default_options="-J-client -J-Xss2m -J-Xms32m -J-XX:PermSize=32m -J-Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -J-Dsun.java2d.noddraw=true -J-Dsun.zip.disableMemoryMapping=true"

Add "-J-Duser.language=en -J-Duser.region=US" to the end of this line

netbeans_default_options="-J-client -J-Xss2m -J-Xms32m -J-XX:PermSize=32m -J-Dapple.laf.useScreenMenuBar=true -J-Dapple.awt.graphics.UseQuartz=true -J-Dsun.java2d.noddraw=true -J-Dsun.zip.disableMemoryMapping=true -J-Duser.language=en -J-Duser.region=US