access denied

[Guest milkman]

I have recently purchased a Maxtor 500 gb One Touch 4 external hard drive. I

formated it to my computer and it worked fine for a couple of days but now

when I try to access the hard drive from my start menu, it tells me access

denied. I can unplug it and get in to via auto run. How can I resolve the

issue of having to unplug the external to gain access to my files? I'm trying

to run this on a Sony VAIO laptop with Windows XP pro. Any suggestions will

be greatly appreciated!