Some kind soul from /u/ found a solution to the 'NetLocalGroupGetMembersã®ã‚¨ãƒ©ãƒ¼ã§ã™' problem, if you still can't figure out what to do about it you should try this:
'Yes, as I said before your account should have admin priviledges. And this shitty installer is checking it - but not the way you'd expect it, as the only thing it's checking is if your user belongs to ADMINISTRATORS group.
Yes, exactly ADMINISTRATORS.
And if you don't have genuine english windows, then your admin account belongs to group called ADMINISTRATOREN or ADMINISTRADORES or, don't know, WATENDAJI (google'd in swahili). And you're fucked, cause installer didn't find you in ADMINISTRATORS group - hence you got no rights to install, k thx bye.
tldr;
- create ADMINISTRATORS group
- add your user (with admin rights) to it
- ???
- PROFIT!!!
BTW, obviously a genuine japanese system is fine too. As I never had genuine jp OS in my hands, I can only suspect they don't use runes with group/user names, so it's ADMINISTRATORS here too.'
It worked for me at least.