system hard drive plugged in as external access denied

i plugged a hard drive out of a laptop into my computer as an external and when i try to go into the user documents it says access denied. ive tried unchecking read only ive tried sharing it and it still gives me the same error message does anyone know whats going on?

os=xp

 

Try this http://support.microsoft.com/kb/308421

If you don't have a security tab you have to disable simple file sharing.

 

Just to add onto this, you cannot disable simple file sharing in XP Home. However, in Safe mode it is already disabled, so there is an alternative if you find yourself in this predicament.