Porting Program Data to New Computer (Alternatives?)

I usually run the OS (windows) on the "C" drive and keep the bulk of my data on a "D", "E", "F" etc. drives.
Some third party software allows one to designate where data is located during install, BUT other third party
software does NOT offer this ability. When moving to a new computer (or now M$ forced move to Win-11),
what is the best alternative to get data ported. As I see it (re program data keep in a propriety format -- or-- unable to specify where data will reside):

1) If this data is already kept on a data drive, it is readily available after upgrade.
2) For data that resides on the "C" drive along with the program, try and identify the directory (files) where that data is kept
and copy to another drive.
3) If one can't id the directory (files), then maybe registry splunking may help. Otherwise ??