I'm just doing a bit of net checking...the first link is a bit long. Please take the time to read it.
First Link
I'll put this in here as well. Could be a good read, though I admit, I only read stuff like this and pick out key words, phrases, tone, and intent....
Second Link
There are various other readings on the net that you can have fun with. Bounce your "Signature.dat" file through google along with "ffxi" and have fun.
Personally, I'd kill it. Check and follow the advise in the first link. Please keep in mind though that if your fix eats your machine, you'll be loading up again......