Where do I find gnucash data?

[JOHN OGDEN]

I'm reaching the stage of envisaging the possibility of porting all my gnucash data to a new PC. Problem: I can't locate the current data files.
The program files are on drive D. (Why? My PC had a significant rebuild five years ago in which the two HDs were configured as two drives, D and E, and a new SSD was installed as drive C). It has been absolutely fine so far -- never put a foot wrong -- but I'm beginning to feel that I must soon prepare for worst case. All data files (at least, those I know about) are backed up regularly on an external HD.
One obvious answer (I guess) is export/import) but is there no better way? John
Revd Dr John Ogden 0118 969 6319 07746 621447