Converting WMV to MP4 I just joined this community and hope my question is acceptable since it is quite "noob" like.

I have a .wmv video file that is 1280x720 and causes windows media player to abort after excessive memory usage. I converted like 5 minutes of it to .mp4(x264) and it played nicely. 

The file is 1.55gb when i converted the whole thing to mp4(x264) it went to 809mb, using Any Video Converted app. Does this sound like im losing quality or is it because mp4 has better compression ratio?

Do you guys know what is the the best mp4 video codec to output the file to preserve quality if the above is an issue. If i should use a different codec or format please let me know what the best would be to preserve quality?

Also what would the right bitrate setting be for the codecs? My options are (xvid, mpeg4, x264) Bitrate 768? or 4000? (these seem to be default)
All that matters is if the MP4 looks good to you. Of course, you may be able to compress more. There is no set bitrate to use. More complex or rapidly changing visuals require greater bitrate. Most converters use x264 to generate the converted video stream, and x264 offers a CRF mode which adjusts the bitrate based on the visual content complexity. If your app allows you to apply that mode, select a CRF value between 20-28 with lower values producing better looking but larger files.

I suggest switching to Handbrake, which is a better pedigreed tool for casual users. I also suggest using Potplayer or VLC to play video files - both are more robust than WMP.