Persisted data is stored in SumatraPDF-settings.txt file. In
portable version the file is stored in the same directory as
SumatraPDF executable. In non-portable version, it's in
%LOCALAPPDATA%\SumatraPDF
directory.Starting with version 1.6 we also persist thumbnails for
"Frequently read" list. They are stored in subdirectory
sumatrapdfcache
as .png files.See
https://www.sumatrapdfreader.org/settings/settings.html
for more information about all the settings which are currently
stored and
https://github.com/sumatrapdfreader/sumatrapdf/blob/master/do/gen_settings_structs.go
for what to change in order to add new settings.