I know this question is asked multiple time and there are some alternative answer also.So please don\'t close with some other link because i have added that link below.
I had face this problem and got solution too. Follow these steps after close your adt -
1.Re install java I will suggest jxpiinstall to be install
2. Execute that file adb.exe
3. Set the envirnoment path again
4. And Here you can have your working adt
I hope this will help you.