Unattended Execution Account in SSRS

Question

Q1: why would I want to have an Unattended Execution Account?

Q2: if I don\'t use an Unattended Execution Account, which account is used to run the reports?

Q3:

Answer 1

Your questions are probably answered by this MSDN article. For Q1 "Why?":

• Send connection requests over the network for reports that use database authentication...
• Retrieve external image files that are used in report...

On question 2: the Unattended Execution Account doesn't determine who runs the report. It just determines the above two things. The report is executed by the Report Server, and that process is running under its own account you configured.

On question 3: see the "How Account Information is Stored" section in the linked question. I'm not sure why a change in the Config Tool wouldn't be immediately effective, you may have to debug that seperately (try to restart things once or twice, etc). If you can't figure that one out be sure to start a new SO question with the details on your situation.