Unfortunately, you can't just plug in an XP disk and expect it to work. The drivers and registry settings for the XP disk is still looking for the hardware and programs on the old system. Not finding them, they system will often blue-screen or simply fail to boot (blinking cursor).
Ideally, what you would do is install both drives and format both.
Install XP onto the first drive.
Once XP is installed and up to date, reboot your system.
Insert the Windows 10 install media.
If the Install program does not start immediately, run the Setup.exe program.
When you get to the type of installation, select Custom Install and select the second disk as the install location.
Once Windows 10 is installed, let it run it's updates and reboot.
On this reboot, you should be presented with the option of which OS to run.
-Wolf sends
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