I have installed virtualbox on a fedora 9 installation . I am using an XP quest . Windows XP works but I can't get the usb ports accessed under XP . How do I set the permissions for the usb ports to be available to the XP quest ? The

Are you running Virtualbox as root or sudo? I ran into a couple of problems because I was running it as a regular user.

I was running as a regular user . I have reinstalled virtualbox as a root
user and can use the usb ports . There should be some files that allows access to the usb ports as a regular user , but I can't find them.

USB in Virtualbox 1.6.2 on Fedora 9.
-------------------------------------------------------

1. Make a file for starting script on boot:
su
"root password"
touсh /etc/udev/rules.d/51-usb-group.rules
with next content, filled in your favorite text editor (lets say nano /etc/udev/rules.d/51-usb-group.rules):

##########################################################################
SUBSYSTEM=="usb_device", RUN="/etc/udev/scripts/set-usb-group '%c'"
##########################################################################

2. Make a folder:
mkdir /etc/udev/scripts
and file inside:
touсh /etc/udev/scripts/set-usb-group
with next content, filled in your favorite text editor (lets say nano /etc/udev/scripts/set-usb-group):

##########################################################################
#! /bin/sh

ret=false
if [ "$1" != "" ]; then
if [ -f /proc/$1 ]; then
chgrp usb /proc/$1 && \
chmod g+rw /proc/$1 && \
logger udev/set-usb-group: `ls -l /proc/$1`
ret=true
fi
if [ -e /dev/$1 ]; then
chgrp usb /dev/$1 && \
chmod g+rw /dev/$1 && \
logger udev/set-usb-group: `ls -l /dev/$1`
ret=true
fi
else
logger udev/set-usb-group: Called without device arg
exit 0
fi
if ! $ret; then
logger udev/set-usb-group: Setting permissions on device $1 failed
fi
##########################################################################

3. Change an owner of file and attribute:

chown -v root /etc/udev/scripts/set-usb-group
chmod -v go-rwx,u+rwx /etc/udev/scripts/set-usb-group

4. Find ID of vboxusers group in User and group manager (I have 501).
Add new row to /etc/fstab

##########################################################################
# devgid=501, 501 - это номер группы vboxusers
none /proc/bus/usb usbfs devgid=501,devmode=664 0 0
##########################################################################
Do not forget to add new line.

5. Reboot.

the following should solve the problem without requiring to run VirtualBox as root:

0. su

1. lsusb (and find the particular usb device you wish to activate)

2. chmod a+rwx /dev/bus/usb/bus/id
(where bus is the bus id, id is the device id)
(example: chmod a+rwx /dev/bus/usb/002/013)

3. Restart / or start virtualbox and your usb device should be accessible.

VirtualBox is designed to be run as a regular user. Only the installation has to be done with root privileges. If it doesn't work for a regular user then something is mis-configured.

Which version of VirtualBox are you using and where did you get it from? Only the PUEL versions support USB devices, not the OSE versions. Have you tried running the VirtualBox USB configuration analysis script from this LQ post?