Unattended Software installation

Hello All:

I was wondering if there is a way to install software on remote client
machines (XP and VISTA) without using the RDP or Group Policy. I have tried
using the PSEXEC (Mark Rassianovich's pstools), but had limited success,
also tried remote installer trial version and it didn't always work.

Cheers.

If you're up to paying the money for it System Center Configuration
Manager 2007 will be released soon. Also New Boundary Prism Suite is a
great remote installation utility. All of which cost money and alot of
time though.