After you've made all necessary adjustments, you may start now: Switch to the program you'd like to record and click on the red button in the tool bar or select record video in the DVBViewer menu. During the recording, the button will be greyed out; a second click stops the recording.
You can record more than one channel at once as long as it is on the same transponder. Just switch to the first channel, start the recording, then switch to the next, start another recording and so on... All manual recordings are listed in the timer programming window (see below), too. The default recording time is 180 minutes.
You have to consider the following things:
Modifications to the TV display (frame size, aspect ratio, brightness/contrast, minimizing the DVBViewer to the tray) do not influence the recording. With DVB the original stream is saved to your harddisk, it is not modified in any way.
Active LAN/Internet connections should be avoided, they could disturb the recording process which may result in lost frames.
Although the recording process is resistant to most other activities, this mainly depends on the efficiency of your PC. With entry-level PC there shouldn't be any background activity.
If you want to use other programs while recording, it is advisable to preset the DVBViewer in the recorder-control-window to a high CPU priority so that all other activity shouldn't interrupt the DVBViewer.