Win XP Pro PC taken off the head office domain and hooked it into a workgroup
in a branch office. Name was changed and settings changed (via System
Properties / Computer Name).

First, the PC still keeps asking for Ctrl-Alt-Del password when switched on.
I have checked in User Account but can see no way to disable this.

Secondly, the PC happily uses a printer on the network and accesses the
internet via the ADSL modem/router. However, there are shares on other PCs
in the workgroup and this PC cannot access them, even though the user has PC
admin rights. It will not even show the other PCs in the group, although
they can see it. I tried setting a share folder but the other PCs cannot
access it.

Any ideas, please? Thank you.