Hello Mohd, and welcome to Seven Forums.
Did Windows 7 come preinstalled on your laptop?
If so, what brand and model number is it? We may be able to help you with how to do a factory restore of Windows 7.
If this a Windows 7 you installed yourself, then you could also create a bootable Windows 7 installation USB flash drive to use instead. USB Windows 7 Installation Key Drive - Create
Hope this helps for now,