Infor CRM software is designed to use a Windows service account for several functions. While you can get away with using a local system account everything is running on a single machine, best practices for Infor CRM call for a domain account. WebDLL is the account name Infor CRM uses by default, but you can use an account name you like. The account should be a local administrator on all the servers running CRM functions. Although it does need to be a domain account, it needs no admin rights on the domain itself, just on the local servers.
If you ever need to change the service account after you have set up Infor CRM, there are three places you will need to change it. First, open the list of services and go to the ones that start with Saleslogix. Locate any of them that are running as the old service account and change them to the new service account. You will need to restart the service to get it running under the new user. (Saleslogix DB Eventing, Saleslogix Job Server, Saleslogix Server, Saleslogix Speedsearch are the ones I commonly see.)
Now open the Administrator program and go to the Admin account. Change the Windows ID for the Admin account from the old service account to the new one (no need to import data from Active Directory).
Now open IIS, and go to the Application Pools. Look for the Application Pool that hosts the Saleslogix services. (It is likely the one that is not running as ApplicationPoolIdentity.) Right click that pool and choose Advanced Settings. Go down to Identity, and change from the old service account to the new one. This one will need an IISRESET to take effect. You are now running Infor CRM under a new service account.