Does not appear to be a valid iTunes library

From Deep Thought

The iTunes Library is sad.

1 Problem
2 Fix
3 According To Microsoft
4 References

Problem

The following error message appears every time iTunes is started on a Windows/XP system with more than 3GB of RAM installed (4GB on our test system):

The files "iTunes Library.itl" does not appear to be a valid iTunes library file.
iTunes has attempted to recover your iTunes library and renamed this file to
"iTunes Library (Damaged).itl".

This error occurs every time the system has been rebooted and iTunes restarts.

[edit]

Fix

This note was located in the Apple forums:

Add the /userva=2800 switch to the boot.ini file.

[edit]

According To Microsoft

This is NOT an official Microsoft post but something found on the Channel 9 MS Site by one of the MS coders.

- PAE mode is always enabled on Vista and XP SP2.  It is required for hardware DEP / NX.

- 32-bit Client versions of Windows (XP, Vista) will never support more than a 4GB 
address spaces, even with PAE.

- 32-bit Server versions will support it, but this is very much the wrong solution for your
 use.  Even disregarding the fact that your machine isn't a server and Server OSes are
 expensive, you need to consider that the reason XP and Vista won't use PAE to address 
additional memory is that many device drivers (like, say, Nvidia video drivers) often don't 
play well with PAE.

- The /3GB switch should never be used.  It exists for very specific server scenarios.  It 
will probably make your machine unstable, and none of your applications will make use of it.

- A 64-bit OS can address huge amounts of memory, and it does not need the remap feature. 

- If you happen to have a motherboard that doesn't actually support more than 4GB worth of 
physical address space, even a 64-bit OS won't help you.  Nothing will.  These boards simply
 do not support 4GB of RAM, end of story.

The right solution for everybody with more than 2GB of RAM is to install a 64-bit OS.  
The end.

Well, some points here:

The /userva=2800 switch stopped itunes from crashing
The /3GB switch allows windows to report at least 3GB available RAM (versus 2 otherwise)
Even 64-bit windows XP does not properly utilize 4GB of RAM, in fact neither does the "standard" Vista release. If you truly want to use that 4GB of RAM you'll need Vista 64-bit editions which area separate download.

While MS guy knows more about MS Windows internals, we hope, we tend to focus on real world usable results. The /userva switch fixed the problem and whether or not the /3GB switch makes the system unstable our test system has been running fine for months until this iTunes snafu started.

[edit]