SpecProc2Browser requires that your PC is running a web server.
You can use any server software you like.
The default installation of SP2B assumes that you are using Microsoft Internet Information Services (this is a Windows feature, you just need to enable it).
SP2B only need the simplest of servers; it is only looking at pages on localhost.
You only need to know where the root folder is on your PC as that is needed as part of SP2B configuration.
For example, if you are using IIS (see below) then the default root folder is C:\inetpub\wwwroot
In the simplest sense you only need to do these four things:
1. Install a web server
2. Configure SP2B to align with the server's web root folder
3. Ensure the folder below the web root has write access
4. Test
Open a browser.
Type localhost
If you get a web page then you have a server running.
Now make sure you know where the server root file is.
IIS already installed, just waiting for you to enable it.
Apache much more intimidating to install.
If you are just using the web server to support SP2B then neither needs configuration.
IIS seems to come with file access errors that need you to set folder privledges. (See https://sourceforge.net/p/specproc2browser/blog/2023/04/file-access-errors/)
Apache uses identical folder priviledges, but seems to be less hassle.
Microsoft Internet Information Services - IIS
This is a Windows Feature.
Press the Windows key and start typing "Turn Windows Features On or Off".
Choose Internet Information Services and leave everything at default.
You most probably have to restart.
Test it is running - See "Are you already running a web server?" above.
Alternatively search "how to install iis on windows"
The home page, downloads link takes you to here:
https://httpd.apache.org/download.cgi
But you actually get the executable from one of these places here:
https://httpd.apache.org/docs/current/platform/windows.html#down
ApacheHaus only distributes the web server (which is the bit you want). Most of the other links bundle in services that are not needed to support SP2B.
This takes you to here:
https://www.apachehaus.com/cgi-bin/download.plx
You will need the x64 version.
What you get is a zip file not an installer.
C:\Apache24\htdocs
https://www.rebex.net/tiny-web-server/
It's a lovely super simple thing, but it does not support space characters in file names. Plus it doesn't operate as a service
Don't bother with this one as you will undoubtedly have filenames that somewhere in the path contain spaces and you will need it as a service so it starts and stops with Windows.
There are loads to choose from.
Search for "Locahost web server free"
You will have to follow their installation instructions.