Make sure that you install the new version (64 bit or 32 bit) in a new empty directory.
The only thing that may be shared is the INI file, type SHOWMACROS to see where it is for each version. The 64 bit INI file is not the same as the 32 bit, but all 32 bit installations will probably eventually use the same INI file.
Sorry for the delay - mail went to mpeforth.com, which is only read once a month or so.
