Hey there fellas, looking for a bit of quick assistance (time is of the essence)

General rundown is as follows [disclosure: linux illiterate]

In the process of my installation, I went from

C: XP OS Partition
D: xP File Storage

to:

C: XP OS partition
D: XP File Storage
Swap Partition
Linux Partition

By shrinking/separating my D: partition multiple times.

Fully installed Ubuntu just fine, ran it and configured it for the better part of 2 hours. Went back to try to get into windows, selected windows XP from GRUB. It began to load, flashed very briefly to a logon window screen (old school, win-2000 style) and then moved to the pale blue "loading windows" splash page, where it hung up.

Went back, booted into safe mode, and it boots just fine. Boot regularly, and windows loads until the log-on screen, in which case I get a translucented-out screen with an alert saying "logon message: your account has been disabled. please see your system administrator: OK"

Any idea what the heck I did wrong, and how I should go about fixing it?

I wish I could give more help but it sounds like its something wrong with your windows. With windows i found the best and only fix is just reinstall it....

I would guess this is where your problems are. What exactly did you do and why? The Grub bootloader basically points to where the windows bootloader should be and it seems to be doing its job as windows starts to boot but fails so mbostwick is right, you did something on your windows bootloader. You might be better off on a windows forum?