I wanted to know if is it allowed to record the game alone first and then time it using the video, i'm asking this because whenever I try to record the game and the timer at the same time it makes the timer to lag a little bit at random points of the game, causing it to freeze and skip around half a second once it unfreezes, and I would really prefer this not happening. Yeah I know I should get a better PC but this is what I have for now :]

if your timer match with the result screen, why not

You could always use Bandicam. It has a feature where you can set a custom recording window. I've never had trouble with lag.

You could use Fraps and record it at half size. It doesn't really take that much processing power that way but your videos may look like potato depending on what resolution you're playing at.

I also sometimes install the games I'm running on a flash drive that way there's no interruption between gameplay and recording. If you do this I recommend optimizing the flashdrive you are using in the advanced property tabs that way it'll load faster and windows can set up a cache for it.

You will have to eject it every time before you unplug it tho so you don't corrupt any files but this method will guarantee faster load times while leaving your harddrive free to focus on saving your video.

Hope this helps :)

Ok i'll see what I can do, thank you all for your responses :D

There is a program named ZD Soft Screen, it is extremely soft and simple to use, and it has a free version. Maybe it is worthy a try.