DB21009E This command must be launched from a
command window running with full administrative privileges.
Problem resolution in Windows 7
command window running with full administrative privileges.
Problem resolution in Windows 7
Well I have been receiving this problem in Db2 v9.7 on Windows 7 from the day I started working on it.
In our company all the desktops were updated to have WINDOWS 7 running in them.
I logged in Windows 7 with "administrator" user and installed Db2 V9.7,and while configuring the instance just made sure that the instance is not automatically started when is system is booted.This started my problems
As our company doesn't give all the users admin privileges at the operating system level,I was not able to start the Instance after logging in with a standard user.
Every time I issued "db2cmd" at the run prompt
DB2CMD Windows invocation in Windows 7:

and tried starting the Instance by issuing "db2start" I got this error.
"DB21009E This command must be launched from a command window running with full
administrative privileges.
SQL1092N "USERNAME" does not have the authority to perform the requested command
or operation."
DB2CMD PROMPT WITH ERROR MESSAGE:

I tried adding the user to the "db2admins" Group and "Administrators" group but still there was the same problem.
Resolution:
After adding the user to "Administrators" group at the operating system level, whenever you invoke db2cmd window try to follow these steps
1. Click on Windows 7 START Button
2. In "search Program and files " search bar type "db2cmd" when you find the db2cmd in the program list then right click on it and select “Run as Administrator” from context menu.

3. This should bring elevated db2 command prompt with full Administrators rights.
4. Issue "db2start" from this window and this will start the instance.
Method 2:
1. Click on Start and type db2cmd in search bar
2. And now press crtl+Shift+Enter
3. This will bring up the elevated db2 command prompt with full Administrators rights.
Method 3:
Disable and Turnoff UAC(User Account Control) in Windows 7 from Control Panel
Note: Please keep in mind that if you are not a part of "Administrators" group then you need to enter username and password of administrator user to access elevated db2 command prompt.