Can't install gcc with cygwin on Windows 10

This app can't run on your PC

cd C:cygwin
cd C:cygwinsetup-x86_64.exe -q -P wget -P gcc-g++ -P make -P diffutils -P libmpfr-devel -P libgmp-devel -P libmpc-devel

The above command makes no sense. It shouldn't start with cd as you are already in the correct directory.

Try the following commands (which work here):

cd C:cygwin
setup-x86_64.exe -q -P wget -P gcc-g++ -P make -P diffutils -P libmpfr-devel -P libgmp-devel -P libmpc-devel

Note:

• This assumes you have a 64 bit version of Windows.

• If you have a 32 version of Windows you need to download the 32 bit version of Cygwin, which has a different installer.

The most recent version of the Cygwin DLL is 2.5.0. Install it by running setup-x86.exe (32-bit installation) or setup-x86_64.exe (64-bit installation).

Source This is the home of the Cygwin project