Try redownloading - something might've gotten corrupted during the download. If that doesn't work, find a new source for Titanium and redownload. If the issue still persists then you probably have bigger problems than just EQ not working, and you might want to consider reformatting and reinstalling Windows. Barring that, defrag your hard drive and clean up your registry before downloading - uninstall useless stuff, delete unnecessary startup entries, etc. More than 10% fragmented disk space = bad.
From
techfifty.org:
[Error 6001] and other critical errors can occur when your Windows operating system becomes corrupted. There can be numerous causes of this error including excessive startup entries, registry errors, hardware/RAM decline, fragmented files, unnecessary or redundant program installations and so on.