Accord to Microsoft, the time until expiration for an invitation when using Windows Vista or Xp are both 6 hours.
penutbutter
The best way to learn about the Windows remote assistance would be via the Microsoft website. In their help section, they offer an entire explanation for the Windows remote assistance.
1 Open the Windows Remote Assistance window that is waiting for an incoming connection. 2 Click the "X" on the upper right corner of the window. 3 Click "Yes" when asked if you want to close the session
Remote Desktop and Remote Assistance
If you have a legal copy of Windows 7, then it's free for you.
RDP. Remote Desktop Protocol (RDP) is used by the Windows Remote Desktop and Remote Assistance utilities to connect to and control a remote computer. Remote Desktop and Remote Assistance listen at port 3389.
Possibly because if the receiver of the invitation uses a shared computer, so it is there so that someone else can't use the invitation.
Click on start button and type in "System", choose the one which is labeled in the image below.Choose "Remote Settings" in tasks list on the left.Check "Allow Remote Assistance connections to this computer" box, and you can click on "Advanced".Now you can extend the time of invitations in Vista Remote Assistance by resetting the number in box.
If your using windows go to remote assistance and put in the other computers internet protocol (ip) address. Easier if you have Windows Live Messenger you can easily ask people if they would like remote assistance.
This depends on what program you are using to connect to the computer. If you are using the in-built Windows Remote Assistance, all you need to do is open up the remote assistance window and click disconnect.
remote assistance
the remote assistance utility