Question1:)
What have you changed on the PC since May? Adding new harddrives/devices which required you to open the PC for any reason?
These changes could include:
Updating graphics drivers.
Updating Motherboard drivers.
Changing harddrives.
Adding new devices and mis-connecting powercables inside the PC, so the gfx card nolonger gets the power it needs.
It could be a corrupt file somewhere within FFXI. If you've done any registry editing, .dat swapping, or any other 3rd party programs they can severely ***** up FFXI.
I'm going to assume since you've been playing since the game was released, that your PC is definitely capable of playing FFXI, and meets minimum requirements. Erasing the harddrive is not a magical fix. If something is wrong with your PC such as overheating or some other malfunction, then you're just giving yourself extra work and losing alot of saved files. :)
My first suggestion would be to uninstall FFXI completely, then re-install it. Now is a time where you'll be biting your fingers off if you didn't save the discs and/or the POL booklet, because you -DO- need the registration numbers in the book. SE will not give them to you over the phone, even if you can give proof of who you are. (credit card info, billing info, past bill amounts for the past 3 years-nope. THey clearly state DO NOT LOSE THIS INFORMATION.) Just a heads up.