after 2 days I solve the problem... WHAT A STUPID PROBLEM!!!!!
I controlled the path of JAVA_HOME that was: C:\Program Files (x86)\Java\jdk1.6.0_17\bin
I don't know but in the past it doesn't give me any problem... but in this occasion I thought that the problem was here... infact I changed the path in
C:\Program Files (x86)\Java\jdk1.6.0_17 and the start.demo is now OK!!!!!
YEAHHHHHHHHHHHHHHHHHHHHHHH!!!