Will be adding new Windows 7 disk to 12.x system ->how do I head off trouble?

I have a 12.1 system that dual boots a dying XP disk via grub. I currently chainload over to that disk and it has been working just fine. Here is my grub file as an fyi

----------------------------------------------------------------
default 0
timeout 8
##YaST - generic_mbr
gfxmenu (hd0,1)/boot/message
##YaST - activate

###Don't change this comment - YaST2 identifier: Original name: linux###
title Desktop -- openSUSE 12.1 - 3.1.10-1.29
root (hd0,1)
kernel /boot/vmlinuz-3.1.10-1.29-desktop root=/dev/disk/by-id/ata-WDC_WD5000AAKS-22YGA0_WD-WCAS81064250-part2 resume=/dev/disk/by-id/ata-WDC_WD5000AAKS-22YGA0_WD-WCAS81064250-part1 splash=silent quiet nomodeset showopts vga=0x37d
initrd /boot/initrd-3.1.10-1.29-desktop

###Don't change this comment - YaST2 identifier: Original name: failsafe###
title Failsafe -- openSUSE 12.1 - 3.1.10-1.29
root (hd0,1)
kernel /boot/vmlinuz-3.1.10-1.29-desktop root=/dev/disk/by-id/ata-WDC_WD5000AAKS-22YGA0_WD-WCAS81064250-part2 showopts apm=off noresume edd=off powersaved=off nohz=off highres=off processor.max_cstate=1 nomodeset x11failsafe vga=0x346
initrd /boot/initrd-3.1.10-1.29-desktop

###Don't change this comment - YaST2 identifier: Original name: windows###
title Windows
map (hd3) (hd0)
map (hd0) (hd3)
rootnoverify (hd3,0)
makeactive
chainloader +1
------------------------------------------

I plan to upgrade first to 12.3 from a clean DVD install (backups etc. to other internal drives).

Then I will install a additional new 1T disk I bought and install an OEM Win7 pro on that. I want to keep the XP disk for now, if only to pull data off but I'll trash it later.

I have no experience installing Win7, nor am I yet familiar with 12.3.

Does anyone have any gotchas that would save me lots of repair time? Is there a step-by-step I could refer to?

All help is much appreiciated