When I try to run any DB2 command in Windows Vista, Windows 7 and Windows 2008 I get the following error:
C:\Program Files\IBM\SQLLIB\BIN>db2 list db directory
SQL5005C System Error.
Resolving the problem
The cause of this error is because you may not have picked "Run as Administrator" when installing DB2.
If you right click on any icon you will have an option to "Run as Administrator":
You can either do this every time you want to open a DB2 Command Window or you can uninstall and reinstall DB2. Before installing DB2 right click on db2setup.exe and select "Run as Administrator", see screen shot above.
For further discussion on this topic, visit this developerWorks forum thread: