Can't map drive to c$ usning Admin pwd

[squibtone]

For some reason I can't map a drive (c$) to another XP
Pro machine using Administrator password. This is a new
stock install of XP Pro in a workgroup....everything is
working fine but this...can see the workgroup and all
machines but for some reason XP is not accepting the
Administrators password. If I go to the machines I can
log in using the Administrator name and password.

All the XP Pro machines are the same Compaq EVO's
All have Internet connectivity and are in the same WG
All I want to do is map to c$