Portable mp4 editor

Hi all,
Was hoping for a little advice.
I need a portable program that will edit an mp4 file.
It needs to be frame accurate and hopefully doesn’t re-encode.
I was downloading avi’s but uploader has changed format.
I need portable as i can’t install anything on the computers i use.
I use 2 computers, one has win 7 and the other has the dreaded vista.
So needs to be able to run on both.
I tried the program i was using with the avi’s which is avidemux 2.4. ???.
That will only do it in what it’s calling a safe mode.
But it loses all frame accuracy and is unusable.
The other day i seen on here of later versions of avidemux.
But when i try editing with updated avidemux version i can get as far as making starting and ending points, but when i go to save file, windows tells me it has a problem and needs to close the program.
So am i somehow doing something wrong within the program.
Any help most welcome or even a recommendation of something else that may be suitable.
Just a reminder that it needs to be portable as i have no way around that.
Thank you for your time.
I have a program to convert to avi so that i can use avidemux that way.
But i don’t have very much time on the computer and especially the one running vista is very slow and is converting in real time or less and i can’t wait that long.
Answer #1
Aimersoft Video Studio Express and Video converter Ultimate may be helpful.
Both available in portable versions..Search in Apps..
Answer #2
Thank you for the reply.
I’ll have a look later on and keep you informed on how things go.
Edit.
Ok i had a look at the program but atm i haven’t worked out how to use it lol.
I’ll have to look at it next week now as i’m a bit busy.
Edit
Unfortunately the aimersoft video studio is proving too hard for me to get to grips with.
It’s also too slow for what i need as i have limited time on the computer so speed is the essence.
Also when i finally figured how to cut my file, the resultant cut file turned out to be bigger than the whole original file.
I may try the video converter route and see how that goes.
What i’m using now is fine but doesn’t hurt to try something new.
But i was hoping to just plain cut the mp4 so as to not lose quality.
Thank you so very much for your reply