Despite everything your real world experience tells you, the fact of the matter is that the "Read Only" box of a Properties window for a folder in Windows XP has absolutely nothing to do with "Read Only". It actually designates a customized folder. A very good explanation from Microsoft is in the following article:
"You cannot view or change the Read-only or the System attributes of folders in Windows Server 2003, in Windows XP, in Windows Vista or in Windows 7"
< http://support.microsoft.com/kb/326549 >
If you are really having problems writing this folder, try asking your question again with more details.
HTH,
JW