[wix-users] Issues when Major Upgrade an InstallShield package

[Persson, Magnus (SE-TLX)]

We've been using InstallShield for 20 years and are frankly fed up with 
all bugs and workarounds required to us it.
WiX is the perfect replacement but until the first upgrade (i.e. from 
InstallShield to WiX) there are a couple of things I need help with.

When I launch the new WiX package that will Major Upgrade the existing 
InstallShield package, a dialog will popup during 'Validating install'.
This dialog will have a textbox with the text "Windows(r) installer 
(Process Id: 4808)" and I can select 'Exit', 'Ignore' or 'Retry'.

The only way forward will be to click on 'Ignore' which will cause the 
upgrade to require a restart at the end (which is fine).
I assume this additional MSI process is some hack within InstallShield 
but is there a way to prevent this scenario?

After the WiX installer has finished there is still a leftover in the 
ARP control panel applet and the reason for this is again an 
InstallShield hack 
(HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall\InstallShield_{Product 
Id}".

Is there a good way to detect the product id of the InstallShield 
package beeing major upgraded so the registry key can be removed by the 
WiX package?

Thanks,
Magnus