I formatted my computer from windows 10 to windows 7. Now the ethernet cable,wifi and usb ports are not recognized. If I go in device manager they all have a yellow !. What alternative do I have to get the drivers? I dont have a CD/DVD reader on the laptop.
Put another OS on a USB drive, e.g. Ubuntu 16.04 LTS. Go to BIOS/UEFI, enable legacy boot, and change boot order and other settings to allow booting from USB. Almost all systems can be set to boot from a USB drive, even though the OS does not recognize it.
Use the browser on the USB drive to download needed drivers.
Mount the HDD in the PC.
Copy drivers to a convenient folder on the HDD.
Reboot and install them.
BTW, you might prefer an alternate OS, which can be tested from the USB without need to install it.
On another computer, download all the drivers needed for your laptop. Remove your laptop's internal hard disk and connect it to the other computer externally by using an HDD enclosure (You can buy it from any PC shop) and copy the drivers to it then return it back to its original place and install the drivers normally.