Duplicate IIS Registry Key Values When Installing x86 and x64 MSI

[tippmar-nr]

Description
If both the x86 and x64 .NET Agent are installed via MSI, on a Windows machine with IIS, the HKLM\SYSTEM\CurrentControlSet\W3SVC\Environment and HKLM\SYSTEM\CurrentControlSet\WAS\Environment registry keys will show duplicate values for NEW_RELIC_INSTALL_PATH - one pointed at the x86 install and the other at the x64 install. This could lead to confusion and possible incorrect .NET Agent behavior when loading instrumentation extensions for IIS applications.

Expected Behavior
The Environment registry key should not have a duplicate value. Or it might be better if the installers would detect that the "other" bitness .NET Agent has already been installed and refuse to allow a second installation.

Steps to Reproduce

1. On a Windows machine with IIS installed, install the x86 .NET Agent via the MSI installer.
2. Select the options to monitor IIS applications.
3. Run the same process with the x64 .NET Agent MSI installer.
4. Use regedit to navigate to HKLM\SYSTEM\CurrentControlSet\W3SVC\Environment and notice the duplicate entries at the top and bottom.

For Maintainers Only or Hero Triaging this bug
Suggested Priority (P1,P2,P3,P4,P5):
P4
Suggested T-Shirt size (S, M, L, XL, Unknown):
M-L depending on chosen resolution.

[workato-integration]

https://issues.newrelic.com/browse/NR-152974