1: Why did you try to make D: Bigger, it was only big enough to hold the Recovery Stuff because thats all it was intended to do.
2: Doesn't Partition Magic give you a waring when you try to resize a partition that has a boot record?
I think you may have broken your XP boot Record, but as far as i know those PCs come with customised boot record to Handel Automated System Restores.
Get your hands on a Real XP disk , boot the disk and attempt a Repair install.
Also If you know how use the Recovery Console to run "fixboot.exe" and see if that fixes it fixmbr.exe might be needed as well