can't install apk on motorola milestone droid

I have an apk which i am unable to install on my motorola milest开发者_StackOverflow社区one droid. It gives an error not an apk file! Any suggestions? I am using android 2.1 and the code was developed on Android 3.1 platform.

this is the manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="acb.xiynove"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="12" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".ACB_OnlineScreenActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

You have specified in AndroidManifest that your .apk file can not be installed on systems lower then with API Level 12 (Android 3.2):

 <uses-sdk android:minSdkVersion="12" />

In your specific case this means that you cannot install this .apk to Android 2.1 (API Level 7). You should either lower to android:minSdkVersion="7", or install .apk only to devices with Android 3.2.

As a side note, my guess is that you meant to use targetSdkVersion instead of minSdkVersion. But I might be wrong, as this depends on what APIs you're using.