Steps to reproduce:
1. Create a new Unity Project
2. Create a new script and open it in Visual Studio 2017
3. Go back to he Editor and open Build settings
4. Download an installer for a Build target(e.g. WebGL)
5. Run the installer

Expected result: the installer warns the user about Unity versions running
Actual result: installer also warns the user that Visual Studio is running, which should only happen if you want to install VS along with the main Downloads Assistant

Reproduced on 5.6.0f2, 5.6.3f1, 2017.1.0p3, 2017.2.0b6, 2017.1.0a3 individual installers(Build targets or Editor installers)
Not reprodudeced with 5.5.4p2, 5.6.0b1 or regular Download Assistant across any versions

Verified FIXED 2017.3.0a6