Hi there 3hhh welcome to pchf

, this should be quite simple to fix try some of these
,Also have you changed anything on your computer recently?.
resolve this issue, use one or more of the following methods, and then restart your computer:
•Remove the non-system disk from your boot device. For example, remove the non-system disk from the floppy drive or the CD-ROM drive.
•Change your computer's boot sequence. To do this, you must change your computer's setup and the option that controls which device your computer uses to start from. Make sure that you select a device that has boot files (or operating system files) installed.
•If you start your computer from a hard disk drive, install a bootable operating system (such as Windows XP) on the drive.
So basicly take out any mp3 players, floppy disks, etc and try it 