Well, first and foremost, any repartitioning or reinstalling any OS involves some risk of data loss. Nothing is more important than creating backups of all valuable data, but since that's not an option just know that there is no 100% guarantee!
While I'm fairly new to Linux (just started in February) but I've been playing with computers since the Tandy tape drive days and I've done a lot of repartitioning down through the years, but I have NO formal training of any sort!
Now, it looks like you have figured out how to use Gparted from the Linux Mint Live CD, eh?
And you're quite new to Mint so you've probably not made a lot of complicated modifications, eh?
And you're reluctant to try and edit GRUB's menu list to make both Mint and XP bootable after installing XP, so I must agree with the previous posts recommending that you remove Mint before installing XP, and then reinstall Mint afterwards.
If I were you, from looking at your screen-shot, I would delete everything but hda1 (your data partition), and leave that new space unallocated (aka unformatted) prior to installing XP. In fact, since your data partition has less than 3GB of free space left, I'd fix that after deleting all other partitions and before doing anything else. I'd go ahead and give at least 8 to 10GB of additional space to hda1. (I'm assuming from what you've said that you already know how to "resize".
A few important notes:
(1) I'm assuming that those small bits of "data" or whatever it is; 64.88MB used on hda3 and 65.07MB used on hda4 are nothing you need (or want) to save.
(2) Deleting all partitions but hda1 will free up approximately 43GB of space. After giving your data partition another 10 GB you could still give XP and Mint each 15GB plus, so make your own decision. (I recommend a minimum of 10GB for Mint and 12GB for XP.
(3) All of this pre-partitioning must be done from the Live CD! A common foible is to not pay attention to the little "keychain" next to a partition. While all partitions should be "unmounted" in a live CD session you may have to right click swap partition(s) and then left click "swap off".
(4) I don't like to "stack up" too many changes in Gparted before applying! In this case I'd delete hda3 and then click apply, then delete hda4 and apply. Then you could delete hda5, hda6, and hda2 (in that order) and apply all three of those changes at once. Then do the resize of hda1 (if you choose to) and apply that!
(5) When I'm all done partitioning I like to waste another 10 or 15 minutes and restart the computer and once again open Partition Editor (Gparted) while in the Live CD just to be sure my changes all took effect.
Once you've gotten through all of that you MUST be familiar with the XP installation process!
You didn't say if this was XP Home or Pro, but these screen-shots are fairly good:http://www.petri.co.il/install_windows_xp_pro.htm
This is the scariest part of the procedure! Take special note of step 7 in that tutorial! Now you know why I said to leave the space "unallocated" (aka; unformatted)! Ideally we want to use about half of the unallocated space for XP but honestly at this point the most important thing is that we don't wipe out that data partition, so I don't care if you use the whole darn "unallocated" space!!! (If that should happen we can fix that easy as heck with Gparted and give you some space for Mint!)
Once the whole XP install procedure is done (don't bother with software installation or updates because Windows splatters unmovable crap all over a partition, OK) it's time to restart and see what we have! I sure wish we had a backup of that data partition!!!!!!!!!!
If all is well then we need to run the Live CD again and go straight to Partition Editor. Lets see if we have an unallocated space large enough for Mint w/swap. 10GB or more will be fine, but if XP hogged the whole space, no sweat! Just "resize" the new XP partition (remember I said to leave it "virgin" so this should be fairly quick).
And, well, you've installed Mint before! If you have a data partition (hda1), and an XP OS partition (should be hda2), and an unallocated (gray space) left I would personally choose "Guided - use the largest continuous free space", but ONLY IF you have a totally unallocated space to install to! Otherwise go Manual!
NOTE: Not having a back up of your data really scares the hell out of me. So many things could go wrong it's downright scary!
Please run my ideas by someone else before just doing it! This is what I would do, that does not mean it's the best way!