It seems that recent version is dependent with winrt api, that is not supported in WIN7.

Starting from version `2020.06.16`, `opencl.dll` is dependent on winrt api, i.e. `dumpbin` of MSVC gives the following results

```
CFGMGR32.dll
api-ms-win-core-winrt-string-l1-1-0.dll
api-ms-win-core-winrt-l1-1-0.dll
KERNEL32.dll
ole32.dll
ADVAPI32.dll
MSVCP140.dll
VCRUNTIME140.dll
api-ms-win-crt-heap-l1-1-0.dll
api-ms-win-crt-string-l1-1-0.dll
api-ms-win-crt-convert-l1-1-0.dll
api-ms-win-crt-runtime-l1-1-0.dll
```

while previous version (`2020.03.13`) is
```
CFGMGR32.dll
KERNEL32.dll
GDI32.dll
ole32.dll
ADVAPI32.dll
VCRUNTIME140.dll
api-ms-win-crt-heap-l1-1-0.dll
api-ms-win-crt-string-l1-1-0.dll
api-ms-win-crt-convert-l1-1-0.dll
api-ms-win-crt-runtime-l1-1-0.dll
```

But unfortunately ` api-ms-win-core-winrt-string-l1-1-0.dll` and `api-ms-win-core-winrt-l1-1-0.dll` are only supported after Win10. This will lose support for Windows 7.
The binaries are taken from anaconda.

Han

Start by comparing the OpenCL loader artifacts from versions 2020.06.16 and 2020.03.13 with MSVC dumpbin, as described in the issue. Trace the build or dependency inputs that introduced the WinRT DLLs and verify the resulting opencl.dll no longer requires them while retaining Windows 7 compatibility.

Written by the indexing model from the issue text.