Windows NGEN NativeImages Folder (C:\Windows\assembly\NativeImages)

Bottom Line: It is safe to clean up obsolete NGEN images in NativeImages using the official .NET NGEN CLI utility. Running ngen.exe executequeueditems will NOT corrupt installed .NET applications.

What is the NativeImages Folder?

Located at C:\Windows\assembly\NativeImages_v4.0.30319_64 (and NativeImages_v4.0.30319_32), this directory is managed by the Native Image Generator (NGEN) in Microsoft .NET Framework.

When you install .NET applications, NGEN pre-compiles managed .NET assemblies into native machine code binaries stored inside NativeImages. This speeds up application startup times by bypassing JIT (Just-In-Time) compilation.

Over multiple .NET Framework updates, obsolete pre-compiled assembly images accumulate, consuming 3 GB to 12 GB+ of disk space.

Can You Delete NativeImages?

✅ Yes, it is safe to clean up via official tools.

• No app crash risk: Active .NET applications remain 100% safe.
• Safety rule: Do not delete the NativeImages root folder manually; always use ngen.exe or official servicing-packages)-packages)-packages)-packages)-packages)-packages)-packages) commands.

How to Safely Clean Up NativeImages

Method 1: Using NGEN Utility in Command Prompt (Admin)

1. Open Command Prompt as Administrator.
2. Run NGEN to purge obsolete native image task queues:

   C:\Windows\Microsoft.NET\Framework64\v4.0.30319\ngen.exe executequeueditems

3. To uninstall unused native image compilations:

   C:\Windows\Microsoft.NET\Framework64\v4.0.30319\ngen.exe update /force

Related Guides

• Learn about deleting [Windows Assembly GAC].
• How to clean up WinSxS folder.
• Check if you can clean NuGet packages.