Windows 7 - Installing WinXP as dual-boot with existing Win7, partition confusion

Acer Aspire 7551 laptop, came with Windows 7 Home Premium x64 already installed, and I've done very little (if anything, really) to tweak or change anything, until now. I'm trying to install WinXP for dual-booting (for playing a few older games that don't like Windows 7 at all).

Followed this thread's instructions (step 1 of the "Windows 7 installed first" method) which led me to this thread to prepare the single HDD with a new partition, 100GB in size, gave it drive letter X: and named it WinXP.

Trouble is, in following the steps in that thread to create the new partition, Windows 7 Disk Management never asks me whether I want the new volume to be a Primary Partition or an Extended Partition/Logical Drive, and it defaults to creating X: as a 100GB Logical Drive - which isn't detected by the WinXP setup CD. It never gives me the option to choose to make a Primary Partition. What am I missing here?

Partitions visible in Disk Management:
[no name][no drive letter] - 12.70GB - Healthy (Recovery Partition)
System Reserved [no drive letter] - 100MB - Healthy (System, Active, Primary Partition)
ACER C: - 351.40GB - Healthy (Boot, Page File, Crash Dump, Primary Partition)
Unallocated space - 101.56GB

I did find this answers.microsoft.com thread whose answer is that I must convert the disk to "dynamic", however, the thread here (linked above, creating the new partition) warns in Step 10 specifically NOT to change to dynamic, as it could make Windows 7 unbootable. ??? Confused...

Use free Partition Wizard bootable CD to create a fourth Primary partition for XP install.

If you need to add any further partitions, you'll need to convert one of the OS partitions to Logical to add within it.

Awesome, thank you, looks like this will do the trick. One question though, it is "seeing" the other partitions, but doesn't seem to be "seeing" the C: drive letter on the ACER volume. And when creating the new partition, I can select to make it a Primary Partition, but it won't allow me to assign a drive letter, neither during creation or after (using the Partition -> Change Letter menu item). Is it critical that the new partition gets a drive letter, or can I assign one afterwards in Windows 7 Disk Management?

EDIT: Nvm, got it - PW was just showing *s for all partitions, but I went ahead and created a new one, and as expected it wouldn't let me change the letter, but Disk Mgmt in Windows 7 showed me that PW gave the new partition E:, and let me change it in 3 clicks. Should be all set now!

Well, not so much. Disk Management in Windows 7 shows all the Partitions, and my new one is X: Healthy, Primary Partition, 101.55GB. Only the SYSTEM RESERVED (no drive letter) partition is noted as Active, while the C: partition is noted as Boot, Page File, Crash Dump, Primary Partition and is 351GB in size with 184GB free.

Booting into the XP Setup disk however, it still only detects one partition, C:, with a size of 131GB, all free (that number appears completely arbitrary since it doesn't match any number anywhere else). It was seeing the same thing before when I was only able to create the X: partition as a Logical Drive, before my OP.

So my confusion is in following the Dual-Boot install tutorial, the screenshots from Step 1 showing the partitions in Disk Management look just like what I see, but his screenshot from Step 5 (partition selection from within the WinXP Setup) shows all three partitions including the new one created in Step 1, but I only see one partition (existing C: ), not the one I created in Step 1 (new X: ).

Almost thinking I should remove the partition and boot into WinXP setup with unallocated space, and let WinXP Setup create a new partition itself with that unallocated space. Would that work, or cause more problems? I'd really like to follow the tutorial steps one-by-one, but I'm stuck here.

Here's a screenshot of Disk Management:

and here's a cameraphone pic of the WinXP setup partition selection screen:

Yes, if XP setup won't see the partition you made then delete it in Disk Mgmt and see XP CD then detects it and will create it as a New partiiton, full NTFS format before install.

Bummer - I deleted the partition in Disk Mgmt, leaving unallocated space, but WinXP Setup still only sees the C: partition and no unallocated space from which to create a new partition for itself. The only thought I have is that the storage drivers in WinXP Setup still aren't fully compatible with the hardware (I already ran into the 0x0000007b BSOD during Setup and changed the SATA setting in BIOS from AHCI to IDE just to get to where WinXP Setup would run), but unfortunately Acer's support site has only Windows 7 drivers for my model (Aspire 7551), so I'm not sure there's anything to be done from here.

Change the SATA setting back to AHCI.

As you have Windows Pro installed, take a look at XP mode:
Windows XP Mode - Install and Setup

I tried XP Mode last year (it was one of the first things I did after installing Windows 7 Pro on my desktop), can't remember why I didn't like it or why it didn't work well for what I wanted, but I remember uninstalling it and not trying again. Might be worth another look. Unfortunately it's not an option here as I only have Home Premium on the laptop this thread is about. I've updated my specs in the User CP.

In other news, I had a flash of inspiration and remembered that I had slipstreamed SP3 into a WinXP install disc a while ago, but I had been using the original for all my efforts outlined above. Thinking maybe there'd be an updated driver in SP3 for my ACER's hardware, I dug it out and gave it a shot - like magic, WinXP Setup now sees all of the partitions, even the two non-C: ones for System and Recovery, and the unallocated space (and that's after setting the SATA setting in BIOS back to AHCI). Sheesh. How much work & frustration I could have avoided if I had just started out with "the latest and greatest" version.

Thanks gregrocker and theog!

We'll need to remember to check for SP3 installer as this can solve these issues on its own. It's hard to remember everything about XP when we've got so many fixes for Windows 7 to recall. But this has solved issues before so it should be tried first.

Good work in sorting this out on your own!

You can mark your thread solved at the top.

Now you have Win XP install take at this tutorial:
System Restore Points - Stop XP Dual Boot Delete - Vista Forums