1. Log on as Administrator.
2. First you need to turn off simple file sharing if it's on. To do that, click Start | My Computer. On the Tools menu, click Folder Options, then the View tab. Go to Advanced Settings and clear the box that says Use Simple File Sharing (Recommended). Click OK.
3. Now navigate to the folder you want to own, and right click it. Select Properties from the context menu.
4. Click the Security tab, click the Advanced button, and click the Owner tab.
5. In the Name list under "Change owner to," click Administrators. If you also want to take over ownership of everything within a folder, check the box that says Replace owner on subcontainers and objects.
6. Click OK. Remember that this only works on files and folders stored on NTFS partitions. Objects stored on FAT partitions don't have owners or file level permissions. You can't turn off simple file sharing in XP Home edition, but you can take ownership by booting into XP in Safe Mode as Administrator, and then following steps 3 through 6.