Can't program nano's using laptop

My old Dell optiplex has no problems programming pro-mini's using the serial-to-USB driver board or the nano's using the standard USB cable.

I now have a new Dell laptop that works fine for the mini's, but for the nano's I get the following error:

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00

I take the same sketch back to the Optiplex, move the USB cable over to that machine, and programming the nano is no problem.

Have I failed to set some parameter in the device manager (WIN-10)? The Optiplex is running Win10-pro 64 bit and the laptop is running Win10-home 64 bit.

Is the version of the IDE on the laptop more recent than the version on the Optiplex? On the laptop you may need to go Tools>Processor>ATMega328(Old Bootloader).

The Optiplex is ver 1.5 and the laptop is 1.8.6. I've had some of these Arduinos in the parts bins for a couple years. I had no idea the bootloader had changed recently (recently for me).

I looked in the processor list on the laptop and I don't see a selection for ATMega328(Old Bootloader)

Thanks.

IDE 1.8.6 should have the 'old bootloader' option. Check which version of the boards manager you have; it should be 1.6.21 or newer. There seem to be some issues with 1.6.22 so I suggest 1.6.21.

The original Nanos changed in the beginning of this year and come with the newer bootloader; newer clones might or might not have the newer bootloader.

I had board manager 1.6.22 installed, so I installed 1.6.21 and got this error

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x82

I installed 1.6.23 and got this error

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xfe avrdude: stk500_recv(): programmer is not responding

The only difference from the initial problem is the response code. When I start the download, I know the system is resetting the nano because it already contains a sketch and I can see the reset happening in the attached I2C display. I just loaded manager 1.6.20 and the error message is the same except the response code:

Still no "old bootloader" tag in the boards list.

Now, however, when I look at the list of board managers it continues to say "1.6.22 installed", but looking at the dropdown list of available managers, 1.6.21, 1.6.22, and 1.6.23 are no longer available.

I have IDE 1.8.5 running on the desktop with board manager 1.6.20 and it works fine when I select "Arduino Nano" from the processor list. I just loaded 1.6.20 on the laptop and I get the same error, except a new response code:

avrdude: stk500_recv(): programmer is not responding avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xa4

I just plugged in my USB programmer and put a sketch on a pro mini using the Laptop to make sure I wasn't imagining that it worked. It works. It's just the old nano (this is a CH340G nano board).

Oops, I just realized that the "Processor" line actually has a drop down selection. Sure enough, there is the "old bootloader." Sorry, I was looking for it in the Boards list.

Works good when you make the right selections.