I have Windows XP Professional operating system installed on an Athlon XP 2000 system. A couple days ago on bootup, it is aking for the system disk. Here is the actual message:"ONGELDIGE SYSTEEM DISKETTE ZERVANGE JGE EN DRUCK OPEEN TOETS". I can put the Windows XP disk in the drive and it will continue the boot process. Has any one had this problem?