I have os in pendrive but how to install that

Solution
search rufus. if in case you already made sure your usb is uefi bootable. stick it in. (re)start your pc. and press f8 for the boot menu and select it. or F2/DEL and select it there.

BUT if you meant you have the windows installer, and if you created it with the Media Creation Tool. just stick it in and do like the steps above.


Precisely

OP, how exactly did you get the OS on to the pen drive, and what do you mean by OS
 
search rufus. if in case you already made sure your usb is uefi bootable. stick it in. (re)start your pc. and press f8 for the boot menu and select it. or F2/DEL and select it there.

BUT if you meant you have the windows installer, and if you created it with the Media Creation Tool. just stick it in and do like the steps above.
 
Solution