Constant vs. Variable Frame Rate?

All my video clips are originally from DVDs that I own. I used MakeMKV to rip the DVDs, then Handbrake to encode the episode chapters to mp4. I used Freemake to cut a particular chapter down to a 1-minute clip that I may want to be the opening scenes of my video, which is known as a “fanvid,” a compilation of scenes from television or film set to an audio track. The previous editor’s tech support said “No vfr! Must be cfr!” so I processed the clip as cfr, tried again, still choppy. Here I am with the same issue. The previous vid editor does not support the integrated AMD graphics on my laptop. I can’t tell if that’s the case here.

Looks like I can’t attach anything yet, so here goes:

Windows 8.1
AMD E1-1200 APU with Radeon HD 7310 Graphics 1.40 GHz
RAM 4GB
64-bit OS, x64-based processor