SQL Installation Account also needs to be local admin?
I just thought I'd share this - it might be listed somewhere in the implementation guide but I didn't see it.
For ServiceDesk 7.5 MP1 install I found that the SQL installation account needs to be a local admin on your ServiceDesk server if you use Windows based authentication. Thats the account that you provide that has sysadmin rights to your off-box SQL instance.
If you don't give it local admin rights on the ServiceDesk server then the Workflow install will fail early on with an error in its log :
"Could not run installed as elevated user. Impersonation Failed: Domain = [your domain], User = [yoursqlinstallaccount] Error: 0