I hope your key working properly,Please follow following steps:
1. You will need OpenSSL. You need to download it from openssl-for-windows project on Google Code.
2. Please unzip the folder after that copy the path to the bin folder .
location C:\Users\peterlaw\openssl-0.9.8k_WIN32, then copy the path C:\Users\peterlaw\openssl-0.9.8k_WIN32\bin.
3. Also add the path to your system environment path. After your PATH the environment variable should be set, So open the cmd prompt and type following command:
C:\>keytool -exportcert -alias androiddebugkey -keystore [path to debug.keystore] | openssl sha1 -binary | openssl base64
Type your password when prompted. After this you will be shown a key.