Running Windows XP Pro, SP2

I installed and ran the application fine for a couple days before it stopped working -- launcher stated that it was 'giving up'. Apparently the service was stopped. Unfortunately, I can't get it started again. Reinstallation (after following the wiki instructions for a manual uninstall) results in the following...

The zDesktop.exe service WILL start, and run for approximately 1 second before crashing with an error.

The dialog box that pops up includes the following under Error Signature:
szAppName : zdesktop.exe szAppVer : szModName : ntdll.dll
szModVer : 5.1.2600.2180 offset : 00001010

The application event log is no more helpful...
Faulting application zdesktop.exe, version, faulting module ntdll.dll, version 5.1.2600.2180, fault address 0x00001010.

For more information, see Help and Support Center at...

I have tried uninstalling every other java version on the machine, in case there was some conflict? No dice.

At this point, I am at a loss. I have no idea where to look for clues or what is causing the problem. Any help would be greatly appreciated.