You need to add a reference to ABCpdf from your Visual Studio
Project. This tells Visual Studio to link the ABCpdf assembly into
Typically you will do this by referencing the ABCpdf NuGet
package. Right click on 'Dependencies' and then select the 'Manage
NuGet Packages...' item, click on "Browse" and search for "ABCpdf -
you should see ABCpdf amongst the results from NuGet.org.
If you have run the full MSI installer, ABCpdf is placed in the
GAC, so under .NET 4 you can add a reference simply by looking in
the 'Assemblies > Extensions' section of the Reference Manager.
Just right click on 'References' in your project and 'Add
Reference' - you'll see "ABCpdf .NET" near the top of the
extensions list. .NET 5 and .NET 6.0 do not have a GAC, so while
you can add the relevant reference by browsing to the DLL in the
ABCpdf installation folder, it is probably easier to add a NuGet
If you are using .NET 6.0 your project target is "net6.0"
however since ABCpdf makes use of Windows specific features, more
commonly you will target "net6.0-windows". If you are using .NET
5.0 the equivalent is "net5.0" and "net5.0-windows". If you are
using .NET Classic then your target will be "v4.0" or later.
The ABCpdf NuGet package ships with the MSHTML and ABCChrome86
HTML conversion engines. If you want to use the ABCChrome65 HTML
conversion engine, you will need to reference the ABCChrome65 NuGet
package in addition to the ABCpdf one. Similarly for ABCGecko you
will need to reference the ABCGecko package. Similarly for
ABCWebKit you will need the ABCWebKit package. All these engines
are installed by default if you run the downloadable MSI
You can mix and match the full MSI installer with the NuGet
packages. If you reference a different NuGet version in your
project then that version, rather than the MSI installed version,
is the one that will be used. Be careful as it can be confusing if
you have multiple different versions of ABCpdf in use.
If you are not using Visual Studio, you will need to consult the
documentation for your chosen development environment.