HI ALL!
I Just had the same problem and tried with all my might to solve it looking for forums on google...and after hours of trying I FOUND THE SOLUTION!!
You dont need to format anything..all you need to do is just create a new folder!!!! let me explain :
BEFORE YOU BEGIN: first of all convert the video from any format to .amv .This must be done using the software supplied or you can find the software from websites my version is 3.68
LETS START! 
1. as soon as you plug the device, it is shown as a removable disk on 'my computer'.double click on this icon.
2. there should be a local folder called 'mp4' or something which holds all the files you are copying onto the mp4 player in this folder (here you should find also the sample files supplied with the mp4 player)..
3. when u access this folder create a folder within the 'mp4' folder (noted above) and name it my videos or something like that.when you’re done double click the foler u just created and copy the video files in there.
thats it!then go on the mp4 player go on 'movie' then click on the button which brings the menu up (lets name the button 'X').select the 'LOCAL FOLDER' option using the 'X' button, then choose the folder where u have the videos placed (i.e my videos in this example).
as soon as u click the X button when u select the video it shows you the contents of the My Videos folder u created.THIS IS THE TRICK:when selecting a video to play dont select it with the 'PLAY/PAUSE' button to start playing a video but use the X button (- i.e the button you use to bring the menu up..mine is named MENU on ohers its called MODE..)when u click the X button on the video VOILAAA it plays!!
hope it works for u as it worked for me (it worked on the 3 mp4 players i have !)
cya guys!
MP4 PLAYER .AMV FILES FORMAT ERROR SOLVED!!!!!
hi.
i hav the problem when i joining any chat room n play the songs in my pc,no one can hearing the voice of tracks in the room.but the mic do the work properly.
pls help 2 solve this problem thanks
it didn’t work on me.. T_T
i followed it.. but still, formnat erro.. huhu
if dont work?
This sucked, it didnt work at all, I still got a format error
DIDN’T WORK 
i was in a building and before i read the sign i turn on my infitek mp-4 player,it came on when i realizie it said do not turn on anly electronics devices my touch sreen froze,i could,n turn it off,so i let the battery run down.and now it won,t come back on. can some one help me
It Working for me..! thank a lot solver.. no need to formating again and again..!
this is good man
i did i but ddin’t work
Made A Video Folder after formatting drive and worked Great. This was odd because the Sample video was not in a folder. When it was new but worked?? But all new Videos had to be in the Video Folder.
THANK YOU SO MUCH FOR SAVING ME HOURS OF WASTED TIME - it worked a treat and was able to transfer 30 videos all in one go and they work perfectly- THANK YOU PROBLEM SOLVER
Thanks alot men!!!!!!!!!!!!IT worked!...You’re a genius...:X:X...it was very important to have some videos on mp4...and now..thanks to you...:X:X:X