In order for all these servers to talk to one another they must be in the same domain. First, confirm that the PC server, ALM Server, and DB are on the same domain.

It is possible that when you configure your database to use Windows authentication you left the PC System user set to its default (IUSR_METRO).

Change the PC system identity to the user you are using to access the database for Windows authentication or to a domain user that has the same rights on the databases will allow you to fix the issue.

You use the System Identity Utility, installed on the Performance Center Server, to change the system
user on the Performance Center Server and hosts.

Below information is pulled from the Performance Center and User Information Guide document from HP.

When you change the system user, or a user's password, the System Identity Utility updates the
Performance Center Server and hosts.

1. Prerequisites
When changing the system user, Performance Center must be down. That is, all users must be
logged off the system and no tests may be running.
When changing the user password:
Ensure that each host is listed in the Machines table under one alias only.
In the case of a domain user, when the domain IT team notifies you that the password is to
be changed, you need to temporarily change the Performance Center system user on the
Performance Center Server and hosts to a different user. After the domain IT team has
changed the password of the domain user and has notified you of this change, you need to
change the Performance Center system user back to the domain user on the Performance
Center Server and hosts.

2. Launch the System Identity Utility on the Performance Center Server
a. In the Performance Center Server installation's bin directory, open the System Identity Utility
(/bin/IdentityChangerUtil.exe).
b. Enter the ALM details to connect to ALM.

3. Change the details of the Performance Center user
Enter the relevant details to update and click Apply. The utility updates the Performance Center
Server and hosts, starting with the Performance Center Server.
In the lower part of the utility window, the Machines table displays the status of each machine
during the configuration process.
If the utility is unable to change the user on the Performance Center Server, it stops the
configuration, rolls back the change, and issues a message explaining why the change cannot be
made. Correct the error and click Apply again.
When configuration completes successfully on the Performance Center Server, the utility
proceeds with the configuration of the hosts. The utility attempts to configure all the hosts, even if
the configuration on one or more hosts is unsuccessful. In this case, after the utility has attempted
to configure all the hosts, correct the errors on the failed hosts, and click Reconfigure. The utility
runs again on the whole system.

4. Verify that the system user was changed on the Performance Center Server
a. Open IIS Manager. Under Sites > Default Web Site, choose a virtual directory.
b. Under Authentication select Anonymous Authentication. Verify that the anonymous user
defined was changed for the following virtual directories: PCS, LoadTest and Files (a virtual
directory in LoadTest).
c. Check in the PCQCWSAppPool and LoadTestAppPool application pools that the identity is
the Performance Center user.