I'm sorry if this has been asked and answered already, but I couldn't find anything when I searched.

I recently got a new computer with a 500GB hd, and I reformatted and reinstalled XP Pro from my original disc (to wipe out all the stuff Dell loaded on it). The problem is that the old XP versions aren't allowing more than ~127GB to be recognized. I updated with SP2 which is supposed to allow for larger drives. My question is now what do I do to actually have the full drive be utilized? I see with Disk Management that there is the 127GB drive and then unformatted space with the remainder. I can create a partition from that and format it, but is there some way to just add the space to the main 127GB section (preferably without destroying everything on it)?

Thanks very much to anyone who takes the time to help me. I really appreciate it.

It's simple, use partition magic, it will allow you add the extra space to your main partition without wiping out the data.

Next thing you should do is make a new copy of your XP disk with SP2 or SP3 slipstreamed, then you won't run into this problem again.

If you want a simple free way to do this, download an Ubuntu distro CD (Live CD). Then boot from it. Once it gets to the desktop, there should be an icon that says install. Start the installation, you'll come to a part where you set up partitions. If I remember correctly you are given the choice to let it set up the partitions automatically or manually, pick manual. Use the partition manager to re-size your Windows partition to encompass the entire HDD. Let it write the partition table and then cancel the rest of the installation. Then reboot and make sure windows partition is 500GB. If it does, do a scandisk just to be sure everything is OK.

Now since this is a new installation, you probably don't have much on the HDD to lose. It goes without saying though, if you do have something you don't want to lose, back it up before you proceed with this, as messing with partitions has the slim chance of messing up the partition. It's a remote possibility, but a possibility nontheless. Better safe than sorry.

I've used this very same procedure a couple of times with no issues. Hope this helps.

What type of drive? IDE/ATA? Hope not. Maybe LBA setting in your bios. I donno

just make one partition when you install windows, then after windows is installed, go to:
controll panel
administrative tools
computer management
disk management

from there you can see your unformated space, format it and name it. i have sp1 disk also and a 320gb drive, this works.

never mind you already tried that.
well, the next easiest thing would be to just make a slipstream sp2 disk while you have your machine up, then before you install all your crap on it again, format and reinstall with your slipstream disk.
pain in the butt but it beats buying partition majic or buying a new sp2 disk.

You really have three choices, but in almost all of them you MUST update your Windows installation to at least SP1, and better SP2, before proceeding. Without that update, you cannot handle any single disk volume over 128 GB.
1. Leave it as it is and use Windows Disk Manager to create separate partitions in the unallocated space. With original XP Pro, every one of them will be limited to less than 128GB.
2. As suggested, use Partition Magic or Unbutu to expand the existing partition to include all the space available. Windows itself will not let you change the size of the boot partition. Again, do NOT do this until AFTER you have updated your XP.
3. Get proper instructions, download all the XP update files and software tools you need, and make a new XP install disk with SP2 "slipstreamed" into it. Then start from scratch and re-install XP from this new install disk. With the upgrade included on it, it will allow you to partition and format the HDD in one large volume for the installation.