Upon windows server hosting DB2 reboot you will get an error message “SQL5005C”. This actually refers to “The operation failed because the database manager failed to access either the database manager configuration file or the database configuration file.” This is due to DB2 database utility (such as db2start, db2icrt, restore, or many others) requires that the database manager write to or read from either the database manager configuration file or the database configuration file, and the database manager was unable to access the configuration file.

This is fixed by performing the below steps:

1. Log in to the machine as system administrator.
2. Remove the db2systray by performing the following steps:
a. Windows Start –> All Programs –> IBM DB2 –> Command Line Tools –> Command Window Administrator.
b. db2systray -clean
3. Log off and log in to the machine.

Thanks,
WintelAdmin