My problem was solved by creating a Windows user without an accent or special characters and reinstalling android studio on that user. Another change is to change the environment variables:
Left Click in My Computer > Advanced System Settings> Advanced > Environment Variables
ANDROID_HOME = c:\my_sdk_path
ANDROID_SDK_ROOT = c:\my_sdk_path
JAVA_HOME = c:\program files\Java\yourJavaPath
Add in Path Variable the values:
%ANDROID_HOME%\platform-tools
%ANDROID_HOME%\tools
After changes, restart windows and try again!