Windows serial port DTR handling during and after boot: stuck high!

Question

I use the DTR line of a serial port to trigger the transmit line on my HAM radio (as do thousands of us around the world!), and have since.... windows 3.11 for workgroups!  I recently upgraded my shack PC to one with Win7 on it that then upgraded itself to Windows 10.  It's nifty and all, but during boot, the serial port probing causes the DTR to cycle a few times (XP did this, too), but after it's finished interrogating the port, DTR (and possible RTS, too) is locked on  until I can authenticate and run a program that uses the port to return it to a sane state.

How can I adjust default serial port parameters to NOT leave the DTR high?  I typically use this remotely, and when the applications crash (yeah, I said that), the DTR returns high, and my transceiver then transmits 'forever' a dead signal.  This is un-good, and will cause me to get a warning at some point from the FCC.

Thanks for your help with this; I'm currently installing updates, and setting the flow control to 'hardware', and will check after a reboot!