How to install fastboot adb drivers on windows

-Enter your android device to fastboot mode,
Step4-Connect your android device to computer,
Step5-Open device manager in computer,

Step6-Right click on the 'Android' under 'Other devices' and select 'Update Driver Software...',

Step7-Select 'Browse my computer for driver software',

Step8-Click on 'Let me pick from a list of device drivers on my computer',

Step9-Select 'Android Device' and click 'Next',

Step10-Select 'Android ADB Interface' and click 'Next',

Step11-Do step 6-7-8-9-10 and Select 'Android Bootloader Interface' and click 'Next',

If you have already done all steps above, your fastboot mode is working well again, Congrats!
You can see everything that needs fastboot is working well,

Step12-Do step 6,7,8,9,10 and Select 'Android Composite Interface' and click 'Next'.