Problem Nano CH341 install

I have 2 new Arduino Nano. They use CH341 software. One I can program using "Arduino Pro or Pro Mini". The other I can't program. It has the "Blink" program as the first one had initially. I used the website installer repeatedly but each time it fails to upload the program. Any suggestions. Thanks.

Please provide a detailed description of what you mean by "can't program", including the full and exact text of any error or warning messages you might be getting.

Please provide a detailed description of what you mean by "website installer".

You could try re-installing the bootloader on the faulty Nano.
You temporarily use another Nano (or other Arduino) configured as an ISP programmer to do this.

Arduino Pro / Pro Mini are not the same as a Nano, which do you have? If you actually have a Nano with a CH341 chip on the board, then it should be programmed as a Nano.

The Arduino Pro / Pro Mini uses the same bootloader as the "old bootloader" used on the Nano, it could be that one of your Nano boards is using the current (new) bootloader.

"The other I can't program"
After the program compiles I get the message that the file did not upload.
":avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x8c
Upload error: Error: 2 UNKNOWN: uploading error: uploading error: exit status 1"

I used the website installer repeatedly"
The website is: CH341SER.ZIP - 南京沁恒微电子股份有限公司
I used the app to install the driver - I did this multiple times - after each time it still did not upload.

The other board which is working I can program with "Arduino Nano" or "Arduino Pro or Pro Mini".

I'd appreciate some help.

Maybe the wrong processor selected under tools -> processor when you select Nano in the board menu; try all three options.

Thanks I tried all the variations with "Nano" and "Pro or Pro Mini".
None seemed to work.

Trying to burn a boot loader onto the Nano using a UNO (CH341). Received the message;

"avrdude: Expected signature for ATmega328P is 1E 95 0F
Double check chip, or use -F to override this check."

I don't know how to put "-F" after the command.
Could someone explain how to do it - thanks.