I am a novice have a question about startup on my desktop

Floppy diskette failure is not limited to the floppy disk drive. It's typically indicating that your drive is not being recognized. Meaning your hard drive is either dead, or a cable came loose from the hard drive.

When going into BIOS even though the drive is dead it will still show up because there is a small file in the drive that contains the drives manufacturing information. But you might notice that where it says SIZE OF DRIVE it will say UNKNOWN. If this is so, the drive is dead.  And you will consider replace the drive, or if you need info off the drive, you may try recovering files from dead external hard drive.

F2 is normally the key to get into the BIOS settings. Press "F2" when the first screen appears. Timing is difficult, so you may wish to continually press "F2" until you see the message "Entering Setup." Look for the first boot device, and make sure it's set as the hard drive. You can also disable the floppy drive while there.

You can also try change the boot order so that the hard drive is listed first or otherwise before the Floppy Disk Drive.

The boot order should be as follows.

First priority - Hard Drive

Second Priority - CD ROM drive

Last priority - Floppy Disk Drive

Important: Modifying BIOS/complementary metal oxide semiconductor (CMOS) settings incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of BIOS/CMOS settings can be solved. Modifications of the settings are at your own risk.

If the issue persists, I would suggest you to contact Dell Support for getting any further assistance.

Dell Support: http://support.dell.com/

Dell Drivers - Product Manuals & Warranty Info (left side) - Tech Support and more

http://support.dell.com/support/index.as...

Dell Forums

http://en.community.dell.com/forums/