Monthly Archives: January 2020


I have been working on a new release of my add-in for doing Monte Carlo simulation (and mucho more!) in Excel. You can help me by trying out xllMonte . I am still shaking down the current release so expect to run into problems. The good news is I have the release procedure mostly automated so I can get you a quick turnaround on anything that comes up.

The install process is still too complicated. You have to download and unzip both the setup.exe and xllmonte.msi files and run setup as administrator. I am using the (free)  Visual Studio Installer Project extension to create the msi file.

I’ve used this in the past and it worked fine for what I needed. Then there was a period when Microsoft wanted you to use InstallShield Lobotomiz^WLimited Edition until you find out it was pretty useless and had to pay for the Actually Useful version.

The next thing I tried was WiX. No, not that WiX, this WiX. It was a bit daunting at first, but the more I looked into it, the more impressed I was by their product. These are top-notch software engineers providing high quality tools to solve complicated problems.

The Windows Installer is a big, complicated machine and I don’t claim any expertise in all of its ins-and-outs, but a msi file is just a database. You can use Orca to see and edit (don’t try this at home kids) the tables. The tables declare what state(s) you want to achieve –  e.g., where files get installed, what registry entries you need – and msiexec reads the database and executes the state machine to make that happen.

As I’ve painfully found out, the Visual Studio Installer Project does not give you full access to the Orca database. It gets worse – in Windows 10 the msiexec program runs with very low privilege. So low that you can’t even modify HKCU registry entries!

I use a Certificate Authority to sign the add-in and installer but still get the nasty warnings about installing “dangerous” software. It turns out there is a new CA in town: Extended Validation Certificates.  Money can’t buy you love, but it can buy you trust. At least from Microsoft.

For now you can run setup.exe as administrator, which then runs xllmonte.msi with appropriate privileges, and then you can get up and running.

I am not worried one iota about AI putting programmers out of work. There are an infinite number of fiddly little details that have to be solved to produce a product human beings want to use. Unless, perhaps, AI can train people to be satisfied with crappy products. We seem to be starting down that road…

Of course I’m probably missing a simpler solution. Maybe Windows Store is the right way to go.