Esti

Every time I try to export my video, it crashes my laptop. I have a gaming computer, so I don't think it's a space issue, my graphics card says it's updated, and yet it does not work. I read in one of these forums that saving it as MPEG4 might work so that's what I've been doing. I also made my video into 4 parts because I don't want to crash my laptop! (when it got too long it also crashed) I need this video for Sunday night, any advice for how to export as H264? (and how to merge projects so that I can export as one video instead of 4 separate parts?)