What problems are you experiencing?

Currently, when an application other than ruby(w).exe tries to load Ruby DLL ((x64-)msvcrt-ruby2X0.dll), the ruby_builtin_dlls directory must be added in the PATH environment. Otherwise, the application fails to load the Ruby DLL.

If the following manifest is embedded into the Ruby DLL, no need to add the ruby_builtin_dlls directory into the PATH environment.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<dependency>
<dependentAssembly>
<assemblyIdentity version="1.0.0.0" type="win32" name="ruby_builtin_dlls" />
</dependentAssembly>
</dependency>
</assembly>

So, please embed this manifest into the Ruby DLL (for convenience).
(Currently, the dependency manifest is only embedded in ruby.exe and rubyw.exe.)

Steps to reproduce

1. Download Vim (gvim_8.1.1006_x86.zip) from here.
2. Unpack gvim_8.1.1006_x86.zip and execute vim/vim81/gvim.exe.
3. Type :ruby p RUBY_VERSION Enter
4. gvim.exe fails to load msvcrt-ruby240.dll.

If C:\Ruby24\bin\ruby_builtin_dlls is added in the PATH environment, the Ruby DLL will be loaded and the version (e.g. "2.4.4") will be shown.

If the above manifest is embedded into msvcrt-ruby240.dll, the Ruby version will be shown even without adding the ruby_builtin_dlls directory to the PATH.
To embed the manifest, you can use the mt command from VC++:

mt -manifest msvcrt-ruby240.dll.manifest -outputresource:msvcrt-ruby240.dll;2

This is also the same for 64-bit versions and also for Ruby 2.5 and 2.6.

What's the output from ridk version?