Can you make sure that all applications are closed during the
transferring and deleting of files. Windows doesn't like any
related applications to remain open while transferring or deleting
files.
Say you are transferring music files, make sure that all music
players are closed. Sidetracking a bit, Internet Explorer or any
browser you are using will need to be closed as well. These
browsers usually have some kind of plug-ins related to music and
Windows will refuse to transfer or delete when they are open.
Another question. Do you have administrator rights on your
PC?
Go to Start > Control Panel > User Accounts
You should the word Computer Administrator under your account. If
you can't see, means you can't delete files, nothing to do with
write protection. Files transfer shouldn't be limited, unless your
computer has certain restrictions set.