Access denied for files and folders

the first problem is : access denied for files and folders after reinstalling windows XP SP2, i tried, please let me know the answer by mail:elshaimaa_emara@yahoo.com
1. go to folder and right click
2.Select Properties
3.Click on the Security tab
4.Click on the Advanced button
5.Click on the Owner tab
6.Click on the Edit button
7.In the Change owner to box, highlight my account
8.Check Replace owner on subcontainers and objects
9.Click on Apply
10.Click on Yes to replace all permissions
the second problem is : all files word or excell opened as read only copy at any other computer on the same network.