Hi!
I have two sata HDs. One of these has Debian an Winxp installed. Grub is the bootloader. Grub resides in MBR (on the same disk). Now that I've added that second disk, I would like to test win7 on it.

What I would like to do is to be able to choose -at boot time (maybe in bios setup)- between booting from the disk containing win7 or from the disk containing Grub with winxp and Debian.

I thought that when installing win7 it would let me choose the disk where to install it and here is where the problem arises:

Win7 installer detects my partitions and lists them as if they were not on different disks. What would happen if I choose to install win7 on the partition I want to (second disk, partition1)? Will win7 create a new bootloader?

Now I am a little confused and don't want to keep on going not being sure the results are what I expected.

What steps should I follow to install win7 on the second hard disc not affecting the disc with winxp, debian and grub letting me choose between these two Operating Systems?

Thank you!
Glore2002.-

as a workaround you could install win7, let it install the bootloader, put in the debian installation-disk, choose >advanced>rescue, answer some questions (language, keyboard, etc, it seems as if the installation-process would start), and then choose to reinstall grub. You`d have to edit /boot/grub/menu.lst afterwards, as it will only add the entry for debian. as said: a workaround.
greetings

How about disconnecting the HDD with winxp, debian and grub while you install W7? I think grub can swap HDD ordering during boot so W7 would "find itself" on the first HDD, as it was when installed.

I don't think you can do what you want. Windows probably only recognises the other disk as a partition because it is a physically different disk. The problem is that Windows does not recognise anything else. It has to sit in specific early physical tracks on the first partition. GRUB (and LILO) do recognise other systems, so as long as you install Linux after Windows, they recognised that Windows exist and allow you to load it. Windows can't do the same (no, we're not cutting rivals out or just ignoring other systems - it just works out that way, so why change it?). You must have GRUB as your initial boot and you must have Windows on your initial partition thinking it is all there is. Or you write your own pre-loader.

Would grub's map command work? AIUI it can be used to swap HDD ordering in the BIOS so it would work if W7 uses te BIOS to determine the HDD order (as opposed to Linux which ignores the BIOS an enumerates the HDDs directly).

That's what I always do. I always make sure I disconnect the hard drives I'm not installing the OS onto. If I then want the new OS in grub I can always manually edit it in, that way it ensures there are no MBR woes.

I think this is what I am going to do to make sure win7 doesn't affect anything else.

After installing it. What should I modify in Grub to let my system boot from win7 too?

I really appreciate your help friends.

Glore2002.-

GRUB has to be Disk 1 from start-up. If it can be told to then look at both disks for operating systems and not just its own, you're in.

you should be able to copy the same entry as for Windows XP, but obviously chaing the drive/partition references

See GRUB Tutorial - Windows is installed on a non-first hard disk (Swapping). Just in case W7 doesn't use the BIOS for HDD ordering and does need to find itself on the same (first) HDD it was installed on, you could keep you options open by having a small partition on the W7 HDD for GRUB.