Windows XP Autorun.inf in service pack 3

[georgelucas]

I'm trying to add an entry to the AutoPlay dialog that shows up when a USB device is connected to the computer. The problem is that this entry is not displayed in the AutoPlay dialog.

Autorun.inf

[autorun]
action=Backup now
icon=backupicon.ico
label=Drive for backup
open=backupnow.bat

backupnow.bat

@echo off
C:
cd C:\myfiles
copy /Y * F:

Files on USB-drive

Directory of F:\

2008-04-14  05:00  25 214 backupicon.ico
2015-06-14  02:34  74 backupnow.bat
2015-06-13  16:00  5 test.txt
2015-06-14  04:04  139 Autorun.inf

Settings and OS

OS = Windows XP Professional Service pack 3 (with every update installed)
Format, USB-memory = FAT
HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Policies/Explorer/NoDriveTypeAutoRun = 0

Windows is running as an image in VirtualBox downloaded from Microsoft download center.

Could someone possibly tell me why this isn't working?

Thanks in advance!