Windows 7 Pro and Windows XP PRO “Semi Dual boot”

Windows 7 Pro and Windows XP PRO “Semi Dual boot”

My question is labeled “”Semi Dual Boot” because I have a situation involving WIN 7 Pro and WIN XP Pro on the same computer.

Background --How I got to where I need to make this post

I had a WIN XP PRO, SP3 system installed,(100% genuine Microsoft product key). Desktop system, single hard drive, with 4 partitions, C, D, E, F with C the active boot partition. Works great, boots with no problems, but hardware and XP PRO beginning to show it’s age.
I decided to UPGRADE to WIN 7 PRO. Bought a new motherboard, new processor, a new hard drive and a 100% genuine Microsoft WIN 7 PRO install disk. I wanted to have all of my XP PRO data files, email files, etc available for accessing, so I left the XP PRO hard drive attached to the system, but changed the “C” partition to NON BOOTABLE”.

I installed the NEW hard drive, partitioned into C, D, E, F and set “C” to the boot partition. Install WIN 7 PRO to the NEW hard drive. Got all new hardware installed and working with no problems.

The system now boots to WIN 7 PRO and functions as expected; internet through router and cable modem, printer access, wi-fi access, installed programs working, etc. When system boots, BOTH hard drives are listed; the NEW drive has partitions C, D, E, F, as expected, and the OLD XP hard drive has partitions G, H, I, J, as expected. All the OLD XP partitions are accessible eg, I can start the (installed on NEW hard drive) Excel program in WIN 7 and then open an Excel data file in partition H, no problem. OF course, none of the program files in the OLD XP hard drive will execute.

The “semi dual boot” question. I know you can “ Dual Boot” the WIN 7 PRO and the XP PRO systems, but all the instructions call for a fresh, new install of XP PRO, (assuming XP PRO is being added to the installed WIN 7 and the second part of the Dual BOOT).
Since my “OLD XP Drive” has a fully bootable XP system installed on partition G (which is currently set to non bootable), is there a way to modify or create a boot manager or boot INI that will, at boot time, give me the choice to boot WIN 7 PRO or WIN XP PRO (from partition G by changing it to a bootable partition?
I am new to WIN 7, but willing to learn, and have been told WIN 7 does not have "boot.ini."
Would appreciate suggestions, instructions and/or tips on how to solve my problem

Thanks

new motherboard, new processor,

You need to do a clean install,
As the new MOBO's now have a uEFI BIOS.
How to install Windows 64 bit on a uEFI BIOS:
UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with

For more info on uEFI:
Windows and GPT FAQ
Unified Extensible Firmware Interface - Wikipedia, the free encyclopedia
UEFI and Windows

I would have left the old pc and built a new pc just for windows 7 or you could have added a new drive to your old system and just installed 7 on it, and had the dual boot, upgrading the old pc as much as possible.

With that said, you just can`t swap a drive to a new motherboard like that.

I doubt you have EFI BIOS if you didnt' jump through it's hoops to install Win7 in UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Forums

If not and you're saying you now have XP on different hardware you'll need to run an XP Repair Install or install to Win7 Paragon Virtualization Manager to adjust XP to the new hardware, if necessary supplying the app with the XP SATA drivers for the new mobo.

If you do indeed have EFI BIOS enabled now then you'll need to change to Legacy BIOS to reinstall Win7 to an MBR disk in order to repair XP to start on the new hardware.