Any help here to solve this issue ?
Node1:
bitcoin-qt --regtest --port=8330 --datadir="E:\AppData\Bitcoin-altdir1
bitcoin-qt --regtest --connect=127.0.0.1:8330 --datadir="E:\AppData\Bitcoin-altdir2
bitcoin-qt --regtest --connect=127.0.0.1:8330 --datadir="E:\AppData\Bitcoin-altdir3
Basically, the three regtest nodes should have different data directories (existing directory) and using the same port.
Second, third and additional nodes have to be set to connect to localhost.