Eclipse Widows 7: cntrl+space is not working

Issue:

In windows 7, eclipse content assist (ctrl + space) is not working.

Problem:

In Windows 7, "CTRL+Space" is used to switch the language. So its overriding the key of eclipse.

 Solution:

 1.       Windows key+R, type regedit and click Ok.

2.       Navigate to HKEY_CURRENT_USER/Control Panel/Input Method/Hot Keys 

3.       Select the key named: 

4.       00000070 and 00000010

o    Key Modifiers designate  (02c00000).

o    Virtual Key designates (20000000).

5.       In the right sub-window, there are three subkeys.

6.       Change the first byte in Key Modifiers from 02 to 00

7.       Change the first byte in Virtual Key from 20 to FF

8.       Log off and log back on.

9.       Do not change the Hot keys for input languages in Control Panel, unless you want to do this all over again.

Error starting modern compiler in Eclipse

I have faced the error "Error starting modern compiler" while running ant build script.

When javac is not able to load the proper JAVA_HOME location, we will be facing this error.

Solution:
Edit "JRE System Library" , which is in the java build path -> libraries tab
Set JAVA_HOME path.
Note: set the jdk path not the jre.

Run the build script, it works fine :)