On my Windows Server 2008 R2 (SBS 2011) i have found more than 25 GB of files that *seem* to be junk:

```
%WinDir%\assembly\NativeImages_v2.0.50727_32\Temp\ - 6.9 GB (656 files in 675 folders)
%WinDir%\assembly\NativeImages_v2.0.50727_64\Temp\ - 18.5 GB (1174 files in 1198 folders)
%WinDir%\assembly\NativeImages_v4.0.30319_32\Temp\ - 0 GB (0 files in 0 folders)
%WinDir%\assembly\NativeImages_v4.0.30319_64\Temp\ - 0 GB (0 files in 0 folders)

```

Best visualized with helper utilities such as `TreeSize` (by JAM Software) or `WinDirStat`.

**Main Question:**  

Is it safe to manually delete the `%WinDir%\assembly\NativeImages*\Temp\` folders?

**Bonus Question:**  

Is it normal to have such a lot of data in those temp folders?  

In the "v2.0" folders i have *several GB*! But in the "v4.0" folders I have *0 bytes*.  

So I assume that something must have gone wrong with the built-in mechanisms of `ngen.exe` or `mscorsvw.exe` to clean the v2.0 "Temp" folders.  

I have tried the usual maintenance tasks (with Windows `Disk Cleanup` etc.), but it still did *not* free anything in those temp folders.

--

PS:  

The related question [Is purging %SYSTEMROOT%\assembly\temp safe?](https://serverfault.com/q/619689/292006) is about:  

 - `%WinDir%\assembly\temp\`  

but here I'm asking about:  

 - `%WinDir%\assembly\NativeImages*\Temp\`