Add Domain User to Local Group

If your web service resides separately from the replication server (distributed implementation), then you need a domain user that the web service can use to access the network. Follow the steps below to assign this user to the local IIS_WPG group.

On the web server, right click My Computer and select Manage.
Expand Local Users and Groups and select Groups.
In the list of groups on the right, right-click IIS_WPG (or IIS_IUSRS, which replaced IIS_WPG in IIS 7) and select Add to Group.

IIS_WPG

IIS_IUSRS in IIS 7
Click the Add button and add the domain user.
Click OK.
Click OK on the Properties screen.