Hi there,
Try to reinstall Windows using the Microsoft website. Download Windows 10 (microsoft.com)
Burn it into a bootable drive such as an USB.
And if the option is available create a new partition of your drive.
Select the new partition to install Windows.
And if you have any old files they would be in the first partition.
Hope this helps
Regards,
Sir, i have some important apps and apps data on it for that reason I want to repair this windows.