I have an older laptop with Windows XP installed. Undoing the XP installation is not an option right now (I can't afford to replace the laptop in the next 6 months).

I installed Mint as a dual boot. It works well, but it is for testing only - it could uninstalled with no loss of data. Because I need a Windows machine for my work, I want to test Windows 7 on this laptop.

All of said, what will it take to introduce Windows 7 into the mix leaving the XP installation intact. Can I leave the Mint installation intact? Or should I uninstall Mint and reinstall it after installing Windows 7?

Note: using Partition Magic I can create partitions as needed for Windows 7.

Been a long time since I tried anything like this.
Create a NTFS primary partition for Win7 - it should find the XP and offer a dual-boot (XP and Win7 only) as an install option. Do that - it will over-write the MBR; an issue if you currently use grub{2} from Mint. Re-install grub from the Mint install disk - it will give you a Win7 entry (not XP) in addition to Mint.
When you choose the Win7 entry from grub it will launch the Win7 boot-loader and you will get XP and Win7 (only) as options there.

To my way of thinking ...

• "Dual-boot" is bogus.
• "Virtual machines" (and external USB/Firewire disk drives) are a Wonderful Thing.™ Everyone uses them, so everyone supports them.

I simply purchased a copy of VMWare, figuring (correctly ...) that they would have worked-out the hard glitchy stuff on my behalf. The modest expense, to me, was entirely justifiable. (Yes, I know that VirtualBox will do it, too. But for me, "time vs. reasonable-money" often gets decided in favor of "time." Y'see, I don't have hair-follicles to spare anymore. )

Then, leaving the host system entirely alone, just set up new virtual machines, each of which resides on a separate external disk (perhaps a partition thereof, but "disks are cheap now"), and which has no direct access to the underlying host. (Nor does the host ever directly access them: when the disk is attached, the host will not try to mount it.)

If you don't have a machine new-enough to run VMs, dig a hole in the backyard and move on.

On all reasonably-current Intel/AMD chips, virtual-machine support is built-in to the hardware ... so it works fine and works fast. All of the issues relating to "dual booting" are eliminated. It doesn't even particularly matter what type of operating-system is "the host." Once I started doing things this way, I never looked back.

In the case of Windows, purchase an unrestricted retail version of the OS ... don't try to gerrymander an "OEM" version or what's now installed on some machine. Give the devil his due, and move on. Don't buy the "cheapest" version, and also not "the most expensive." Start the VM, boot the install-DVD into it, and present the new Windows with "a bouncing baby (virtual) machine with one completely-empty disk drive all to itself." It will know what to do from there.

will win 7 even run on the old xp laptop?

it might not even install ,if the hardware will not support it

That's good advice, except ....

1. The whole point is to see if the Windows 7 drivers will work on this computer. In a virtual machine, the network driver - the most critical of all drivers - isn't used. The VM uses the native driver of the underlying OS. That might actually be the perfect solution, but the old laptop maxes out at 2GB RAM. Windows 7 barely runs on any 2 GB machine, and worse so when it's running in a VM (I have used procedure on other 2GB machines, and it was very sluggish.)
2. Once I can afford a new laptop, the new one will run win 7 (because of the work I do). This old one will love Linux - I've already proven that - it will be a match made in heaven. But first I have to be able to afford a new Windows 7 laptop.

As an aside, I'm going to try a USB wireless adapter. If that solves the Windows 7 problem, I have plenty of time to gather up the necessary $$ - as long as I can live with Windows 7 on a 1.6 GHz Centrino® / Core™ 2 Duo processor T5200 - running in native mode, not in a VM.

So, back to the original question: what's the best way to triple-boot XP, Mint, and Win 7 when the XP installation has to remain as pristine as possible, but Win 7 and Mint can be loaded in either order?

Also, I could make an image of the current XP, slick the disk, and on clean metal install The 3 OSes in a proper sequence.

By the way, I've never had a problem with VirtualBox, hosted on both Linux and XP. Go figure.

I won't know until I try. The problem is knowing how to set it up so that all 3 will play nicely together.
Eventually both Windows will be banished from the laptop, and Linux will prevail. Until then I have to jerry-rig it.

FWIW - A while back I installed Win 7 on an old Asus EEE PC that had XP on it. Win 7 actually ran faster than XP did. You need to watch the memory usage, but the OS itself should be just dandy. I believe that system was limited to 2GB of RAM as well. Win 7 was alright with it, it was Thunderbird and Chrome that ate all of the RAM and would kill the system...seriously, Chrome is a masterpiece of memory leaks.

On the EEEPC, did the wireless work with Windows 7? Does 7 fit properly on the screen? How much disk space did it use? My EEEPC only has a 16GB SSD(and 2 GB RAM).

One of my clients gave up on the default EEEPC Linux, and experimented with XP. That didn't last long - terrible performance and how XP fit on the screen. They tried various Linuxes and settled on ~200 units with Easy-Peasy.

On mine I ran ubuntu on EEEPC until that awful interface drove me away. Now it runs Mint. Everything runs well and and I use it daily. There is no problem with drivers or screen fit.

Win 7 had no issues with wireless or the display, neither did openSUSE or XP though.

I don't recall the disk space usage, but I'm pretty sure that's higher than XP.

Installing window 7 after mint will more than likely overwrite grub and therefore will have to use a rescue/installation disk to reinstall grub to mbr.

What sort of a job is it to change the hdd on your laptop, some it is easy and you could invest in some others to allow testing.

I appreciate that this might be a rubbish suggestion if your hdd is buried deep in the bowels of your laptop, but you might be lucky and this idea may help you.

I own 3 dif models of lenovo Thinkpads a T61 running Win XP 32bit, a W500 running Win7 64bit and a newer W520 which has win10 lite atm but I want to install a multi boot with both the Windows OS plus Linux Deb 12 so 3 choices of OS as I have accs and printers that require the Win XP 32bit PS to work plus apps that require win7 64bit to run. then I want to migrate to linux deb for as much as possible and browsing. the TP T61 has a 1tb HDD 2/3 full. the TP W500 has a 2TB SSD and the docking station that both the T61 and W500 can use has a 2tb HDD in ultrabay for BU/Archive files. the W520 cant use that model dock station as its PSU is much bigger. so thats why Im trying to merge all to the W520 but cant find if 32bit and 64bit can play together in VM. I plan to move the shared 2tb HDD to the ultrabay in the W520 thinkpad once the multi boot is set up for easy file swaps. I also have a fresh 264gb thumb drive to put rescue/repair apps and multi boot OS on also so if needed can fix issues as my 2 sons both with IT degrees which wont speak to me for awhile now are zero help. hope somebody can help me here. Thanks Mitch