Maybe:
Courtesy of Nepatsfan....

You need to take ownership of the files. Take a look here for
the procedure:

How to take ownership of a file or folder in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;308421

"Access is Denied" Error Message When You Try to Open a Folder
http://support.microsoft.com/default.aspx?scid=kb;en-us;810881

Good luck

Nepatsfan

OR:
Courtesy of Rick Rogers

Taking Ownership:

Sometimes, in order to get access to a folder, you need to "take ownership"
of it. To do this, you must be using an administrator account, or an account
that has either a higher level of privileges or privileges equal to the
account currently in control of the folder. First, you must be able to
access the security tab of the folder properties. For the security tab to
appear in a WindowsXP Pro system, you must disable simple file sharing in
the control panel/folder options/view tab, it's at the bottom of the
advanced settings. For a WindowsXP Home system, you must restart in safe
mode and logon as administrator.

Right-click the folder, select properties. Go to the security tab and click
advanced. You can take control of the folders on the owner tab by clicking
on your user account, then click apply/ok. Note also that these sorts of
permissions are only available when using the NTFS file system, they are not
supported in FAT or FAT32. More details here:

HOW TO: Take Ownership of a File or Folder in Windows XP [Q308421]

http://support.microsoft.com/?kbid=308421

An additional note for WindowsXP Pro users: This procedure will not help you
recover data if the files are encrypted. All you will be able to do is
delete them. To recover encrypted files you will need the original
encryption certificate or a Recovery Agent from the installation under which
they were encrypted. Without one of these, the files are not recoverable.

    As you've discovered, once any additional administrative user
accounts have been created, the built-in Administrator account will no
longer be displayed on the Welcome Screen.  This is a default security
feature.  By design, the only way to log into the Administrator account
of WinXP Home is to reboot into Safe Mode.  For WinXP Pro, pressing
CTRL+ALT+DEL twice at the Welcome Screen will produce the standard login
dialog box.

    The built-in Administrator account really was never intended to be
used for day-to-day normal use.  The standard security practice is to
rename the account, set a strong password on it, and use it only to
create another account for regular use, reserving the Administrator
account as a "back door" in case something corrupts your regular account(s).

    A wiser course of action would be to create another user account
for your daily use (as you've done), and copy desired the files and
settings from the Administrator account to this newly created user profile.

HOW TO Create and Configure User Accounts in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;279783

How to Copy User Data to a New User Profile
http://support.microsoft.com/default.aspx?scid=kb;en-us;811151