I'm probably slow, but I cannot find a way to transfer Arduino programs I have written on my laptop
to the Arduino program on my PC. I try usual file transfer methods and keep getting error message that it is not an .ino or .pde file and nothing happens. I'm going from a W7 laptop to a W10 PC. Any help appreciated.
if the extensions are not PDE or INO or HEX and you try load them up to an Arduino with an IDE you may face issues such as you are seeing.
Are you trying to move the whole of your sketches folder which is usually best.
If so then in most cases they will fit on any decent size USB stick.
You may want to do the sketches first and then the libraries which are also in the same folder.
Libraries can take up more space and in some cases may need to be moved separately.
If you have a sound Ethernet or wireless setup between the two computers and a shared folder it is a little easier.
It was a little awkward readin just a long sting of text.
Consider being a little more specific and laying out exactly what programs you are trying to use and having line breaks between sections.
Bob.