If you still use workgroups to avoid the need of an active directory server, you need to activate the admin shares like (ADMIN$). The first scan will try to set this key in the registry automatically. Next time, the scan engine can install its agent using the share. In workgroups you provide the identical local admin user account to the scan engine service. As this account exists with the same password on the other workgroup members as well, you can scan the computers then.
If you need to activate the admin shares manually, do the following:
1. Open regedit
2. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
3. Add a DWORD32 value named “LocalAccountTokenFilterPolicy“
4. Apply “1“ to it.
5. It may be necessary to reboot the machine.
It might be cost saving to avoid a server operating system to host a domain. This only applies to small networks.