I have already check the link, thanks for the suggestion.
But I still confuse, how could I rename the password of account "Host", because when I search account with name "Host", there's nothing in table "Users".

Is in your table "Users", there is account name "Host" ?
Cause I couldn't found it in my table.
 

Here's list of column field in my table "aspnet_Users" :
ApplicationId, UserId, UserName, LoweredUserName, MobileAlias, IsAnonymous, LastActivityDate

and there's no "superuser" flag.
What should I do to find it ?

Thanks a lot

Just now I have search and found thread : Host account lost,
there's quote :
"If you can access the database you can go into the Users table and mark your user as a Superuser. Once there you can create more superusers and disable the first one if you need to"

But again, I couldn't mark as "SuperUser" in table "aspnet_Users". When I would to create new user.
Is another way I could do again ?
Or Is reinstalled way the last choice for me in this case ?

Right now, I couldn't do my next task, cause stuck in this case.
Would appreciate any help.
Thanks a lot