I believe I have to get out of the reboot loop that occurs, before the camre can connect to the
tftp server.
No, the 'probe for tftp updater' is done by the bootloader just after power-on.
The bootloop is later when the Linux kernel starts up and at some point objects to the running environment, reasons can be various, and reboots.
Not that it will make a difference at this point - but the 1-line downgrader is a safer choice.
Presumably you are pinging the camera at a 192.0.0.64 IP address?
And the PC is set to a 192.0.0.128 IP address?
And the Windows firewall has an inbound allow rule for 'tftpserve.exe'?
It is possible that your camera has a later, modified bootloader that no longer has the 'probe for tftp updater' feature.
Hikvision removed the tftp updater download quite a while back with the intention of phasing it out.
The next step, and not too hard in practice, would be to connect to the serial console on the camera main board.
Required is a Serial TTL to USB convertor (PL2303HX-based works OK), and a 4-pin 1.5mm micro jst zh connector.
Quite a few posts on 'How-to' for this method.