At your own risk :
regedit : and change what you want, backup before
[HKEY_CURRENT_USER\Software\Novaquark\DualUniverse\Settings]
"InstallFolder"="C:\\ProgramData\\Dual Universe"
"CacheFolder"="C:\\Users\\xxxxxxxx\\Documents\\Dual-Universe-Cache"
"PreviousCacheFolder"="C:\\Users\\xxxxxxx\\Documents\\Dual-Universe-Cache"
where xxxxxxx is your windows user name