For those suffering crash to desktop from launcher... chkdsk may be your friend...
A little background on my situation:
Ran into problems this morning after getting booted last night because I didn't make it to town and log off in time before last nigh's maintenance, and then crashed the client again unknowingly trying to log in when they were starting emergency maintenance this morning. You know the accursed error numbers---9000, 2002. Well, it knackered me up bad--after that, whenever I hit Play... bam.. back to desktop. No error messages... not even in the Windows logs.
Was contemplating a rollback of Windows Updates, then a roll back of the FFXI files from a backup I made a couple weeks back--worst case scenario a delete/reinstall and <uggh> full update from scratch.
Hadn't run my defrag routine in a while, so I fired up Puran and let it do it's whole boot-time defrag business... but this time I went ahead and let it do it's disk check routine as well. Lo and behold... errors were found and corrected.
Game booted fine and I ran to Drybone to log out normal.
So... if you are plagued with the crashing to desktop as you are logging in or launching the game, try to check your drive(s) for errors, enabling the fix option. It's pretty simple to pull up and do--don't have to drill down through the crazy GUI and check boxes. Just open a CMD prompt and type a simple command to run it.
In XP, just go to start/Run and type the letters "cmd" and hit the <enter> key. You will go right to a DOS box with a folder path showing on your screen and a blinking cursor.
In Vista or newer, you need to be in a privileged session. Instead of using the Run box, use the Search box. Type the letters "cmd", but DON'T hit the <enter> key. You should see a link to the CMD command in your results list (should have a black icon by it, a snapshot of the DOS box). Right-click that and select to "Run as Administrator". Now you are in a privileged DOS box.
Now, just type this simple command and press the <enter> key:
This will check your C:\ drive for errors and try to fix them. Do this for each of your drive partitions, changing the letter for the appropriate drive (chkdsk E: /F to check the E:\ drive). If you notice it found errors on a drive---run it again to see if it reports no errors found. Depending on system design, this could take 10 minutes per drive, or 30+...hopefully you don't have a full terabyte of data on your drive. Hate to see how long that would run. YIKES.
Type the word "exit" and hit the <enter> key to close the DOS box when done.
Note: You will get a notice when running it against the system drive that it is locked and can't be performed at this time. It will ask if you want to schedule it to run on the next reboot (Y/N). Respond Y to schedule it and reboot to run the scan.