And this is being seen while running Vista not XP? Here I have ready access to the DocumentsandSettings folder on the XP drive while in XP or in Vista the Vista version with the same name is off limits. The users folder replaces that in the new version.
What you are seeing in the image posted earlier is browsing the XP folder while in Vista with complete access seen there for going into the first PC eye as well as those seeing a large number on the end added to it. The next thumbnail will show more folders below on that.
You may have to create a totally new admin account in order to be able to have ready access if you are unable to assign new permissions to the present user account created when installing Windows. By default however only certain files on the XP drive will see the access denied error being more or less protected system files. First have a look at the screen shot here to get an idea of having ready access while in Vista.
One free tool found is called TakeOwnership that adds a feature to the right click menu when clicking any non vital file or folder. First look over the information on the need for adminstrative access as seen at http://www.petri.co.il/add-take-owne...menu-vista.htm
The free Take Ownership zip file is found along with the blog on that at http://www.howtogeek.com/howto/windo...menu-in-vista/
Surprisingly this same reg mod will also work quite well in XP as well as Vista pointing that as something someone found earlier and discovered also worked in the new version as well. The last option if nothing works would be manually moving files from their present locations while running XP and seeing them go into new folders outside of any created when installing Windows or by a software installer.
That makes them totally free to access regardless of which version or even Linux you happen to be running. The live Linux distros can also be great tools for data rescue when you lose access to any MS drive/partition.