DB2 Express User ID Authority Error I'm trying to create a sample database in first steps after installing db2 Express V10.5
I've looked at the answers provided below, but I'm not able to resolve my issue.
How to grant rights for a user in DB2 Express?
DB2 Express on Windows 7 - Disable security?

Here is the exact error message

Creating database "SAMPLE" on path "C:"...
  Attempt to create the database "SAMPLE" failed.
  SQL1092N  The requested command or operation failed because the user ID does
not have the authority to perform the requested command or operation.  User ID:
"I32129
  'db2sampl' processing complete.


I'm logging on to my computer with a username on a domain managed by my company. My username is actually i321290, not sure if that error is accurate or if its hitting some character limit. While I was installing db2 I created a username and password for db2admin 
which is in the PROD_EXPC.rsp file. 
The DB2ADMNS and DB2USERS groups are created in my local groups. I created local users db2admin, i321290, and I32129 and added each of them to the above groups. The user names aren't case sensitive.
DOMAIN\db2admin and DOMAIN\I321290 are also members of these groups.
I've run the following commands

db2set DB2_GRP_LOOKUP=local
db2stop
db2start


but still receive the same error.
I had the same problem and solved it by adding domain admin user into the local Administrators group on local computer (where I installed DB2 DB).