How to add admin account to SSAS 2012

Question

I am using a Windows 8.1 laptop and I installed MS SQL server with Analysis Services.
I am the only user of the laptop, and my Windows account type is indeed administrator. but somehow it seems this account does not belong to the administrators group.
During SQL server installation, I was stupid enough to forget to add myself as SQL server admin.
Now SSAS blocked my admin access, and I cannot make any changes to SSAS.
That is, I cannot deploy OLAP model, cannot read properties of SSAS instance in SSMS management studio, and of course I cannot add any account to SSAS using the "security" page of the Analysis Services Properties window in SSMS.
Do I have to re-install SSAS, in order to add a server admin account? 
Sorry for potential double posting. I asked a pretty similar question in Windows community
Administrator account does not belong to / inherit privilege from the BUILDIN administrators group?
http://answers.microsoft.com/en-us/windows/forum/windows_8-security/administrator-account-does-not-belong-to-inherit/bd8db7c8-64c2-43ee-9716-3eb0e41766dd
Thanks!
Kind regards,
Liz

Answer 1

Have you tried with admin rights? right click on the SSMS icon and choose the option to "Run as Administrator"  Also add your account to local administrator if its not currently.
By default, members of the local Administrators group are also granted administrative rights in Analysis Server. If you are a administrator of that box you should be able add yourself.
https://msdn.microsoft.com/en-us/library/ms174561.aspx
If you still cant try below:
Check what account SSAS is running under(local system). change that to your account, restarted SSAS, and reconnected with SSMS. Check if you could see the properties, and add your account, changed the startup account back to local system.
http://www.pertell.com/sqlservings/archive/2011/03/ssas-administrator-accounts/