ant build : unable to locate tools.jar. Expected find it in C:\Program Files\Java\jre7\lib\tools.jar
I too had this problem and solved it by setting variables like this :
[1] ANT_HOME - C:\apache-ant-1.9.3[2] JAVA_HOME - C:\Program Files\Java\jdk1.7.0_21[3] PATH - D:\Android_Development\android_sdk\platform-tools\;%ANT_HOME%\bin;%JAVA_HOME%\bin;D:\Android_Development\android_sdk\toolsNote : Set all these in System variables not in user variables.
This solved my problem.
Hope it helps.
To Recover this problems you can just copy the tools.jar from "C:\ProgramFiles\Java\jdk1.7.0\lib" directly into "C:\Program Files\Java\jre7\lib\".You will successfully recover the problems.
It works!..
I solved issue with setting %JAVA_HOME% to start of the PATH. It worked for me when I set it exactly to the start.