Windows Reinstall & NTFS Permissions

[ViRGE]

I'm planning on upgrading my computer this weekend, and have a quick question about how to deal with NTFS. My plan is to install WinXP on a drive that currently just holds data, but because it'll be a new installation, I'm afraid that NTFS's file permissions will lock me out of most of my stuff. What do I need to do so that once I have the new copy of WinXP running, I'll still be able to access/modify/own the data on the drive like I currently do?