Why am I getting: "No system images installed for this target"

Question

I'm having trouble with the Android emulator.

I am running on Windows 10, and here is my environment:

Microsoft Visual Studio Professional 2017 
Version 15.5.6
VisualStudio.15.Release/15.5.6+27130.2027
Microsoft .NET Framework
Version 4.7.02556

Xamarin   4.8.0.760 (fc93f3f5b)
Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android.

Xamarin Designer   4.8.188 (c5813fa34)
Visual Studio extension to enable Xamarin Designer tools in Visual Studio.

Xamarin.Android SDK   8.1.5.0 (HEAD/75f8c6838)
Xamarin.Android Reference Assemblies and MSBuild support.

Xamarin.iOS and Xamarin.Mac SDK   11.6.1.4 (db807ec)
Xamarin.iOS and Xamarin.Mac Reference Assemblies and MSBuild support.

My Android SDK Platform looks like:

and the SDK Tools is:

In my emulator screen, no matter what device I choose, I get the error: "No system images installed for this target".

I clearly have installed the Google ARM System Images. I don't understand why I'm getting the error message. Any help will be greatly appreciated.

Charles

Update 2

I would like to thank York Shen, and Jon Douglas for their help. The Device Emulator now works... well almost.

I installed the Intel HAXM Emulator Accelerator. My console script was:

I also selected the Accelerator from the SDK Tools:

When I try to define a new device using the Emulator Manager, I now get:

Obviously, I still have a problem with HAXM. By the way, if you tell me I have to change my computer's BIOS to make HAXM work, I will give up on Android.

I tried to run a default emulator, and it warned me that I could continue, but without any acceleration. A simulator appeared but my application did not run. My application only runs on iOS and UWP.

I'm going on five days in trying to get the Android Emulators to work. No cigar. I contrast this to my experience with the iOS Emulator. That one took me about 1/2 an hour to get running. It was very clean and simple. I'm thinking seriously about abandoning all software development for Android.

Answer 1

Why am I getting: “No system images installed for this target”

As @Jon Douglas said, you are using a deprecated version of the AVD Manager, you could refer to the docuemnt:

As of Android SDK Tools version 26.0.1, Google has removed support for their UI-based AVD and SDK managers in favor of their new CLI (Command Line Interface) tools.

You could refer to my answer for a more detailed answer about how to solve this issue:

Xamarin with Visual Studio not detecting CPU/ABI system image for emulator, even though system images are installed

Update:

If you use the Xamarin SDK Manager and Xamarin Android Device Manager, you need update to Android SDK Tools 26.0.1 and later (which is required for Android 8.0 Oreo development).

You could read this: Requirements. In your situation, upgrade your Android SDK Tools version to 26.1.1:

Update 2:

You need Installing the Xamarin Android Device Manager, then you could start the Device Manager by clicking Tools > Android Emulator Manager: