windows path is perfectly capable of dealing with the space in the file name.
You can probably open your path variable right now and see a dozen references to program files (x86) folder already in it.
you should not make a new programfiles folder. That is kind of ugly.
look for an example in your path already, and if that does not exist (it really should), look online for the right way to do it.
I just messed with it in a command prompt and it works fine.
path = c:\program files\folder
path (this verified my change, which is local to the one instance of the shell thankfully when done this way)
cd\ (return to c:\
programname (executed a program in the folder under the path to test it)
and it worked.
so just put the spaces in and see if it works, it should.
If I remember correctly the installer of MinGW said it should be installed in a folder without spaces.
Normally on Windows spaces are legal but I guess for programs with a Linux background things are different.
I have installed it on C:\MinGw and it works perfectly.