I am primarily a Macintosh user, and can usually walk a client though any troubles they may have because I have a Macintosh in front of me. If they are on a different OS, things are close enough, or I cam remember, that I can get by.

When trying to help clients on Windows, I get stuck. I do not have access to windows, and even if I did, there are far too many versions of Outlook, all with their various esoteric settings and checkboxes, that I could never see exactly what they are seeing.

I mostly need to just help them with email setup. Something like copilot.com may do the trick.

What is the simplest remote control software out there, ideally, it would accomplish these:

1. No software needed on remote end, or, a single .exe that they can toss when done.
2. I need Mac based software on my end. I do have ARD, which support VNC
3. Free :) If possible, it would be really nice
4. Needs a port forwarding proxy run by the company. There is no way I can get the user to alter their router, or to even plug directly into their WAN for a short time.

On the Mac, I just have them open iChat, and this is all built in, proxying through AIM, looking for the same for Windows and Mac.