@kaliahy Hi, this is usually a problem with your windows installation which is lacking this file along other key components for certain programs to work. Normally these are system files associated with programming components that are obtained through windows update, though some programs bundle them, however this particular message is rare.
Pencil2D bundles the vc_redist.exe installer that is appropriate for your OS architecture (32 / 64 bits) inside the Pencil2D folder you extracted previously.
However if you are unsure about using the bundled installer file, please visit the following official site by Microsoft and under the Visual Studio 2015, 2017 and 2019 section download the vc_redist.exe version that is appropriate for your system (x86 for 32bits, x64 for 64bits).
https://support.microsoft.com/en-gb/help/2977003/the-latest-supported-visual-c-downloads
If you are unsure as to which system architecture you have please look at this FAQ on the second question from top to bottom.