PS C:\vc\vcpkg> ./vcpkg upgrade
The following packages will be rebuilt:
  * icu[core]:x86-windows
Additional packages (*) will be modified to complete this operation.
If you are sure you want to rebuild the above packages, run this command with the --no-dry-run option.
PS C:\vc\vcpkg> .\bootstrap-vcpkg.bat
The property 'instance' cannot be found on this object. Verify that the property exists.
At C:\VC\vcpkg\scripts\bootstrap.ps1:78 char:31
+         foreach ($instance in $asXml.instances.instance)
+                               ~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], PropertyNotFoundException
    + FullyQualifiedErrorId : PropertyNotFoundStrict

Could not find Visual Studio. VS2015 or VS2017 (with C++) needs to be installed.
At C:\VC\vcpkg\scripts\bootstrap.ps1:143 char:9
+         throw "Could not find Visual Studio. VS2015 or VS2017 (with C ...
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (Could not find ...o be installed.:String) [], RuntimeException
    + FullyQualifiedErrorId : Could not find Visual Studio. VS2015 or VS2017 (with C++) needs to be installed.

PS C:\vc\vcpkg> .\bootstrap-vcpkg.bat
The property 'instance' cannot be found on this object. Verify that the property exists.
At C:\VC\vcpkg\scripts\bootstrap.ps1:78 char:31
+         foreach ($instance in $asXml.instances.instance)
+                               ~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], PropertyNotFoundException
    + FullyQualifiedErrorId : PropertyNotFoundStrict

Could not find Visual Studio. VS2015 or VS2017 (with C++) needs to be installed.
At C:\VC\vcpkg\scripts\bootstrap.ps1:143 char:9
+         throw "Could not find Visual Studio. VS2015 or VS2017 (with C ...
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (Could not find ...o be installed.:String) [], RuntimeException
    + FullyQualifiedErrorId : Could not find Visual Studio. VS2015 or VS2017 (with C++) needs to be installed.