Windows won't boot without flash Drive/USB Drive/CD

This problem cause by bootloader, a program that load your operating system. So, if your hard disk (internal) does not have the bootloader it won't boot to windows because no program will load your operating system (Windows XP/7/8/10 etc). In one case (Asus Notebook) the bootloader not installed in C partition (the windows partiton he use to install windows) but installed on the USB disk. So, without the USB disk he can't boot to windows.

So here how to fix it:

First of all Insert you installation Disk (either DVD or USB Stick)

In Windows 8:
When installation windows appear Click Next - click Repair your computer

 click Troubleshoot
 click Advanced options
 choose Command Prompt
Then type: (press enter to execute the command and do it one by one)

bootrec / fixmbr
bootrec /fixboot 

Windows Vista/7:
It is the same method as Windows 8 you need to access the command prompt. to do this insert you installation Disk and select repair. Then select keyboard - Use recovery tools - Command prompt

The type the following command one by one and press enter after each line.

bootrec / fixmbr
bootrec /fixboot

You can also use Bootrec.exe by microsoft instead. I never try it and it is a lot to explain how to use this tools. so I just write the easiest method to fix this =p