C'est du au fait que tu as installé ta verison de xp sans te mettre en tant qu'administrateur ou équivalent. Bref il faut que tu redémarre en administrateur pour te donner les droits.
et pour resoudre ton probleme:
CAUSE
This behavior can occur if there is an incorrect setting in the following registry entry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Explorer\User Shell Folders\Common Administrative Tools
Note This registry key exists only if you upgrade your computer from Windows 98 Second Edition to Windows XP or from Windows Millennium Edition to Windows XP.
RESOLUTION
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To resolve this behavior, follow these steps.
Click Start, and then click Run.
In the Open box, type regedit, and then click OK.
Locate and click (highlight) the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Explorer\User Shell Folders
In the right pane of the Registry Editor window, double-click Common Administrative Tools.
In the Value data box of the Edit String dialog box that appears, type the following line, and then click OK:
%ALLUSERSPROFILE%\Start Menu\Programs\Administrative Tools
On the File menu, click Exit to quit Registry Editor.
Restart the computer.