My environment of phone application development, Android

The following is my laptop computer enviroment:

• OS: Win7
• CPU: Intel Core i3
• RAM: 2G
• Type: 32bit
• IDE: Eclipse3.6
• Target Platform: Android2.2 - API Level8

At first, I used Android 3.1 and API Level12. I found there was no phone interface without keyboard viewer when i started an emulator in taget platform Android 3.1. Every time, when i ran an application on that emulator, it took much time to load *.apk and show the application. I was confused if my environment is correct.

 

Fortunately, when i talked with my friend about this issue, he suggested me for changing the Android platform. I changed Android3.1 to Android2.2. It seems everything is okay and the running is very fast.