[access-denied] PSEXEC, access denied errors

PsExec has whatever access rights its launcher has. It runs under regular Windows access control. This means whoever launched PsExec (be it either you, the scheduler, a service etc.) does not have sufficient rights on the target machine, or the target machine is not configured correctly. The first things to do are:

  1. Make sure the launcher of PsExec is familiar to the target machine, either via the domain or by having the same user and password defined locally on both machines.
  2. Use command line arguments to specify a user that is known to the target machine (-u user -p password)

If this did not solve your problem, make sure the target machine meets the minimum requirements, specified here.