Part of video editing is changing the very nature of the footage you have to express an artistic choice or to emulate a visual style. This can mean a number of things from the way you cut together your shots to exactly how you alter each clip. Digital video filmmakers are often troubled by the way those digital video images come out, mainly because they look so much different from that of regular film. To counter this, and give choices for how the given footage is to be presented to the audience, most video editing programs have filters to make it look like film to some degree. Many of these center on the idea of making it look like a very old piece of celluloid, which is interesting and affects the way the audience views the images. Windows Movie Maker offers a limited form of this, and there are even different levels you can apply.
Go ahead and select the clip you are looking for and drag it into the Timeline. This is not the same with photos as it is with video. If the video clip is already in the Timeline just go ahead and right click on it and choose Video Effects. From here you will be given the classic video effect menu with the list of possible video effects in the left column and the video effects already applied to the clip in the right column. If you go down you end up having four main options. There are three titled Film Age, with three degrees: Old, Older, and Oldest. Depending on the age of that is indicated it will add desaturation, interference, video noise, deresolution, and other types of film degeneration that mimics older film stock. There is also Film Grain, which just adds a certain amount of appropriate film static. Each of these is meant to alter the visuals so that they end up mimicking an older film look, but you cannot change the degree to which each one does. You can use more than one, but it is really best to just use one specific age of film effect and then possibly the film grain if you must. Just go ahead and select which ever you choose, click the Add button in the center, and then the effect will head to the other column.
Getting It Done
This is easiest to do in the Timeline and you can try selecting several clips at once and doing this. You may want to try doing this type of process with an outside application when going after photos.