Quote from: ps1234 on January 01, 2025, 03:27:38 PM

I'm puzzled, because the bitcoin.conf file in C:\program files\bitcoin does not contain anything but comment lines.

That bitcoin.conf file is just a sample, open it and read the comments on lines 6 to 8 for its settings to apply.

Quote from: ps1234

So, how does the program know where to find the blockchain? After all, it's on a separate drive.

You can start bitcoin-qt with --choosedatadir to open its "Welcome Screen" where you can set it.
e.g.: ./bitcoin-qt --choosedatadir

Or as mentioned by ranochigo,
For bitcoin-qt's datadir, it's selected in the welcome screen when Bitcoin Core (GUI) couldn't find the previously set datadir or an existing datadir in the default paths which is %appdata%/bitcoin (will look here first) and %localappdata%/bitcoin (will create here if the default is selected) in v28.0.

Alternatively, if you set the above to the default datadir, you can paste the "bitcoin.conf" file there and type/uncomment the datadir=<path> line pointing to your preferred datadir.

The latter "alternative" works in bitcoind and bitcoin-qt while the former only works in bitcoin-qt (GUI).