Windows 7 turns screen saver on while watching movie

Windows does not view a movie or video running as activity. It just looks at mouse and keyboard movement. Just turn off the screensaver, it's a waste anyway. You should use power management tools to shut the monitor off when it's not in use. Those will take into account if something is running or not, not just if the keyboard or mouse were touched.

Not sure I would turn off the screensaver completely, but I would use power management to set the options for movie watching preferences.
One way is to go to Control panel>Appearance and personalization>change Screen saver> and set the wait time to 2 hours or whatever you feel comfortable with. Then click on Change power settings to adjust monitor shutdown etc. for movie viewing.

Now can I adjust it to where I'm running say the screen saver every two hours but it shuts off the monitor every half hour (sometimes I get careless and forget to turn the monitor off).

control panel-->power options, check which option you have highlighted-->change plan settings--->change advanced settings--> multimedia settings