Your setup is not removed. have a look in your /tmp directory. There is a tar.gz copy of the directory /home/admispconfig, /root/ispconfig and the database. Unpack them in their orignal directories and run the setup again.
x86_64 is not yet officially supported by ISPConfig. We are still working on a reliable method to detect if an installed linux (not the processor) is a 64 BIT version. Most distributions have the same version ifo for 32 and 64 bit.