Reparing Data Archive

After starting GW.exe I get this screen. It looks exactly like the install screen but says its reparing data archive with a progress bar....

Whats this mean?

It means your gw.dat file is corrupt. Two possible causes are:

Bad sectors on your hard disk drive: run chkdsk.
Faulty RAM: run memtest.

It's probably not a bug; it's more likely that you have defective or faulty hardware.

Not a game bug. Moved to Technician's.

More often it's the result of data being corrupted during download, particularly if it's a background download while playing the game over a patchy connection.

If the problem happens a second time, delete your .dat file, and redownload via -image. If the problem happens a third time, then you'd better start looking for faulty hardware.

This happened once to me when I was using Windows Vista on my old laptop. It could be bad sectors on the hard drive that is corrupting it. I would recommend, first, download the DAT archive using -image and letting it sit overnight. If it happens any more, I would replace my hard drive and RAM.

I would recommend running a disk scan using the Check Disc command:
http://support.microsoft.com/kb/315265

I think the bad HD or RAM might be the last resort...just delete and redownload the file with a -image first and see if it still happens. I had tons of these happen to me when they first implemented the force-to-character select option in the game, rather than the log out and back in.