Grub : Windows Boot Terms Explained

In my last post, I talked about setting Windows as the default OS as well as making it appear on top. It involves moving three instructions to the first location. That gives a default option of booting into Windows, as the default value of 0 reads the first OS in the list.

If you check out the last post on How to set Windows as Default OS in Grub, you will see that there are some terms which you will be moving up and down in the menu.lst file. Now, to better understand the usage of this, the terms are explained in a lucid manner here.

root(hdm,n) :

This sets the boot device and mounts the root file system. The boot information is read from the partition ‘n’ , and from disk ‘m’ in hdm. Thus if you have a second windows installed in another hard disk, simply change the value of ‘m’ to 1 after attaching it. Also, if you have a Windows in another partition, set the correct value of ‘n’ to boot from it.

makeactive  :

This sets the active partition and works only for Primary Partitions.

chainloader +1 :

With this command, we can set the boot loader to set the first sector of the active partition in use(given as the value +1), as the location for instructions.

That is all about the boot options of Windows. Additionally, you can use a number of switches to achieve many other results.

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Chinmoy Kanjilal

Chinmoy Kanjilal is a FOSS enthusiast and evangelist. He is passionate about Android. Security exploits turn him on and he loves to tinker with computer networks. He rants occasionally at You can connect with him on Twitter @ckandroid.