I do hope I'm not asking something that's been asked before. I have tried to check past comments for answres/solutions to my queries but I'm new to this so apologies in advance if I'm mistaken.

I'm just looking for some advice and a bit of guidance on the two following topics if anyone is able to help me:

Edits

I have a two-hour film but I only wish to keep two thirty-minute chunks of it. Spcae on computer is tight and the two-hour film comes in at just under 1GB in size. I used Windows Movie Maker to edit the film down to the two chunks but each came in at over 800MB when I was hoping/expecting for it to be closer to 250MB. As my only reason for making the edit was to reduce the size of the file, it seems I'm better off keeping the original as it was. I have a few films like this. It's not just the one.

Have I incorrectly assumed that by editing down the file it would also be reduced in size, or could it be that a change of settings might make a difference?

Video Thumbnails

My films seem to automatically grab their thumbnail images from the beginning of the film and I would like to know if it is possible to grab an image from a later point in the film, a point of my choosing. I can't seem to work out if this is possible so if anyone is able to help and advise me on this that would be great.

Thanks in advance to anyone who is willing to help, and again, I have tried to make sure I'm not wasting people's time by looking for information before making this post but if I have over-looked anything then please accept my apologies.

Catherine