POL won't boot

[Theytak]

I just installed FFXI on my new desktop, but every time I try to boot POL, I get this:
Error code = 20008003
PlayOnline Viewer cannot run under current operating system

The problem is that I used the same installation disk I used for my laptop's version of FFXI. My laptop has the same OS as my Desktop (Windows 7 64bit), and it runs FFXI just fine, and has for years. I've tried everything I can think of to get it going, but I've had no luck.

I've got this serious urge to play again, and I wanna do it on my awesome new desktop, not my horrible old laptop, haaalp

edit for clarity: This is not through steam, though my desktop has steam and my laptop doesn't...