install new windows on the flash ?

When you posted from scratch, can I assume you mean a clean install? If so go to the site below and download the media creation tool. That will create a USB with Windows 10 (1903) and you can clean install from the USB.

https://www.microsoft.com/en-ca/software-download/windows10

https://answers.microsoft.com/en-us/windows/forum/windows_10-windows_install/how-to-reinstall-windows-completely-on-an-m2-nvme/644be6f8-539e-4218-8d40-1c53283d9fc3

https://www.youtube.com/watch?time_continue=9&v=No-ct8pQcIg

@mohdz 

Since you have W10 already installed there is not much you need to do.

W10 will automatically activate once you are connected to the internet. 

Regards,

U2

EDIT: Since you are replacing an M.2 for another M.2 there is nothing you need to do in the BIOS.

thanks for your reply but if i download the windows from the windows site i think i have to add the activate code when i install it right ? i dont have it , but when i donwload the dell os recovery tool theres an option there to download a windows or a support os recovery tool and its recommended by dell , so which one should i download ? after download the windows what can i do in the bios ? because the desktob bios is different from the laptops bios i think

and yes i want to remove the old m.2 from the laptop and add the new m.2 and install the windows on it 

Welcome to the Dell Community  @mohdz 

Use the Dell OS Recovery Tool to create a USB recovery drive that you can use to reinstall the version of Windows or Linux that came with your PC:

https://www.dell.com/support/home/us/en/19/Drivers/OSISO/recoverytool

For a clean Windows 10 install:

You can make a W10 USB flash drive installer with the Microsoft Media Creation Tool, using a 16 GB flash drive using another Windows PC, if your PC is not working.

https://www.microsoft.com/en-ca/software-download/windows10

If you are asked to enter a product key during the installation process, select the 'I don't have a product key' option, and W10 will install and automatically activate once you are connected to the internet.

Here are the steps to create the W10 USB flash drive installer...

Select Download tool now, and select Run. If you agree to the license terms, select Accept.

On the What do you want to do? page, select Create installation media for another PC, and then select Next.

Select the language, edition, and architecture (64-bit or 32-bit) for Windows 10.

Select which media you want to use:

USB flash drive.

Plug in a blank USB flash drive with at least 8GB of space. Any content on the flash drive will be deleted.

After W10 installs, you can install the drivers and available software from your notebook's support page.

Best regards,

U2

The different recovery drive options will restore to a clean drive with the Factory configuration except, from my testing, it will have the current Win 10 version.  I can't of course swear to that but the only way to find out is to try.

The Dell version of the Recovery image looked to me just like a Recovery drive you can make using the Win 10 utility.  When you boot the recovery drive, from the recovery options, you select to recover from a drive instead of recover from an image.

If you have a new drive, you can play a little and get some experience.  If it doesn't work the first time, you can always try again as long as you have the recovery drive.  If something fails, let us know exactly what happened and any messages you got.

There is however, a gotcha, when installing on a Dell System.  They normally set the drives up to use an Intel SATA/PCIe driver. You may need to install additional drivers during the install or change the Bios SATA controller setting.  If the first part of the install goes normally but it won't reboot back into and complete the install, then you are probably seeing this situation.

Your very welcome @mohdz 

Let us know if you need any further assistance.

Best  regards,

U2