The HP ALM Service is the main service that makes QC/ALM serve it's web pages.
You really do not need a user specifed (blank) - it will use the ''Local System Account'' as the ''logged-in'' user to run the service.
The only reasons you may need a SPECIFIC user here would be if you are using SQL-Server in ''Windows-authentication'' mode, or if you have your repository on a network share. Here, the service user also has SQL-Server access or R/W rights to the network share, or both.
If you DO enter a specific user here, beware of the usual problems in Windows with specific users:
- if using a certain person's userid,
and they leave the company, this
userID must change.
- if using a certain person's userid,
and their password changes, it must
change on the service too
- Specific userid may inadvertently
have it's various rights revoked by
some system policy - this may break
the service connectivity to File
system, QC or DB.