I am running Windows 7 64-bit and Eclipse also 64-bit with the latest ADT plugin installed and the Android ADK. All installed as instructed on the Android SDK site.
I found similar issue on my windows. Seems like this happen for 64 bit machines only. To solve this, make sure you have full access permission to all files under the Tools folder in Android SDK directory. For linux/ubuntu, execute the following
chmod -R 777 ../tools
For windows, goto Android SDK directory..
Right click Tools folder > Properties > Go to tab "Security" > Select "Users" > Edit > Select "full control", save and close it.
It should work after doing this