I just rebuilt a computer at work due to a motherboard failure, and upon reinstallation, had a problem with QuickBooks Pro 2008.  When I tried to run the program, all I got was:
“QuickBooks unrecoverable error” as the title of a message box, with contents indicating that the program couldn’t start and asking if I would like to send an error report.

Other key info related to this error was the error code “00585 53668″ at the bottom of the message box, and the error code “0xc0000005″ in the one of the error report’s XML contents.  I searched the usual search engines with a variety of terms and most of the solutions I came across related to uninstalling and reinstalling the .NET Framework (version 2.0) – Of course I did this, to no avail.  Other potential solutions involved reinstalling QuickBooks (which I did, but as expected, resolved nothing, as I had just freshly installed the app in the first place.)

Then, I ran across one post on fixya.com titled “Went to open Quickbooks pro” where another user was also having problems opening QB due to a DLL error.  The recommended solution in this case was to run the “reboot.bat” file in the QB program directory.  I checked the contents of this batch file, and it appeared to re-register a bunch of DLLs.  I ran it, and viola! Instant success.

Relevant to this, but unmentioned above, was the fact that I had reinstalled WinXP Pro onto my user’s existing hard drive from the failed computer, so Windows was automatically reinstalled into “C:\WINDOWS.0″ instead of the usual “C:\WINDOWS” – this was made relevant to this error due to fact that all throughout the reboot.bat file, the commands were registering DLLs in the new windows.0 folder…

So, if you have any QuickBooks Pro 2008 startup problems after reinstalling Windows and QuickBooks, especially if you are using a non-standard install directory for Windows, try running the reboot.bat file in the QuickBooks program directory (typically “C:\Program Files\Intuit\QuickBooks 2008″)

Good Luck!

(This post created to grab search results for QuickBooks Pro 2008 error code 00585 53668 related to an unrecoverable error when starting the program, especially directly after a reinstall onto a used hard drive where Windows is installed into a different directory than “C:\WINDOWS”.)