help with alienware m15x (whithe,green,rose screen after trying to start windows).

Let's see, if I remember correctly, your laptop should have a Phoenix BIOS chip, therefore, 1 long beep at startup would indicate a  RAM error.
If you're okay with working on your own machine, you could try testing your RAM cards by following the proper procedure for removing one, test the computer with the remaining one, and if the problem persists, repeat the process with the other card.
You should verify your BIOS chip first, though, to make sure I am not mistaken.

Other than that, weird graphics effects could also indicate a graphics card issue.
Sorry, can't help you there.

Good luck!

It's ok, I'll check, I've also been tempted to install a new bios in case the bios it has was corrupted but since it gives a screenshot I'm afraid that it will happen in the flashing and it will be bricked :( haha, I will inform you of what happened.

I had an Acer thta did something like that: would boot to Windows, only to BSOD and auto-reboot after making some POST beeps.
Turns out the graphics card was shot, not the BIOS chip.

then the theory that it can be the graph takes more strength. :/

https://youtu.be/qaxyNu0TtSs

To give a reference, my laptop does exactly this, it turns on, it loads the main windows screen, the white screen jumps, but in my case, press what you press and whatever you do does not change the white screen.