For psexec to work right I believe the pc HAS to have a password. Also, unless they changed it, it won't work trying to send a command to XP Home. It has to be professional or higher. Just my 2 cents.
I'm not sure about the password thing on the "sending" PC, since psexec has the ability to set what credentials to use on the machine it is controlling. A password is definitely required on the "receiving" PC.
The OP didn't mention if HS is running XP Home or XP Pro. It seems that the remote computer (HS, in this case) must be running a "Pro" version of the OS.
A few more things I found:
1. Try using the IP address of the server, instead of the name. See if that makes a difference.
2. Make sure the "$Admin" share is enabled on HS.
3. Make sure that File and Printer sharing is enabled on HS in the firewall.
4. The account that you are using on HS has a password, right?
HS is running XP Pro. other pc's on the network can see the server (HS) and i run ultravnc on all and can access it no probs. I just cant get this to fire across....
Tried using the IP i get access denied.
$Admin?? where do i find this? the Drive on the server is shared.
File and print sharing is on.
Yes HS has a password. Computer name is server, account is HS, and password is something!
Tried
d:\tools\pstools\psexec.exe \\192.168.167.100 -u HS -p ******* "C:\Program Files\ Common Files\X10\Common\ahcmd.exe" sendplc A1 ON
d:\tools\pstools\psexec.exe \\192.168.167.100 "C:\Program Files\ Common Files\X10\Common\ahcmd.exe" sendplc A1 ON
d:\tools\pstools\psexec.exe \\server -u HS -p ******* "C:\Program Files\ Common Files\X10\Common\ahcmd.exe" sendplc A1 ON
d:\tools\pstools\psexec.exe \\server "C:\Program Files\ Common Files\X10\Common\ahcmd.exe" sendplc A1 ON
none work