I use Ubuntu Linux and my client and I need to do extensive custom application testing on Windows. (I wish his app were Ubuntu only, but his customers all have Windows.) We also need to stop when we encounter an error in a custom application and then let the other guy connect in to see the screen and to try some things. We can't use virtual machines on our workstations because it doesn't provide this kind of collaboration.
Is there a Terminal Services service on the web that we can purchase from some service or web hosting provider where we can get an XP, Vista, and Windows 7 VM that we can reboot and install software as we desire? (We need to test on these 3 Windows versions.)