I recently had an issue with reinstalling XEd after a manual deletion of my GCII folder. I was able to reinstall the game with no issues, but when I tried to reinstall XEd it gave me an error saying a previous version was already installed. As an attempt to fix this, I went into the registry and deleted the XEd folder, which on Windows 8 64bit is located at HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Massive Entertainment AB\XEd . This did not fix my problem, however. I ran the registry cleaning portion of CCleaner, rebooted, and tried to install XEd again with no success. I could not find any other entries for XEd in the registry with the search function, so what I did instead was search for the data/value '0.02.003', which was the version XEd insisted was still installed. Nigh instantly, I was brought to an uninstallation information key (named as a hash value) which contained the version information for the previous installation of XEd. After deleting it, I was able to reinstall with no problems.


TL;DR: If you can't reinstall XEd, delete its registry key in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Massive Entertainment AB\XEd (64bit) or HKEY_LOCAL_MACHINE\SOFTWARE\Massive Entertainment AB\XEd (32bit). Then perform a registry search for your current version number for XEd and delete the uninstallation folder that is found.