I found the solution.
This is from a DB2 UDB security document:
"Beginning in DB2 UDB Version 8.2, additional security was added to DB2
UDB in the Windows environment. A new option exists as part of the DB2
UDB installation to create two additional groups in the operating
system, DB2USERS and DB2
I'm using IIS on a windows server. I'm having issues trying to connect
to DB2 via PHP.
I can connect to DB2 on the command line on the server.
> db2cmd db2 "connect to emr1u1 user etldbu using "
Database Connection Information
Database server= DB2/AIX64 9.1.3
SQL authorization I