The last three times I have started my computer, the following message appears. Please explain, and advise me?

It means your hard drive is failing. S.M.A.R.T. stands for Self-Monitoring, Analysis and Reporting Technology. When it sensing something is failing, it warns you. The "Backup and Replace" part means EXACTLY that. Backup any data you need, then replace the hard drive.

It looks like American Megatrends is your BIOS,Reading down your Q. Pri slave-hard disk.....status bad,it looks like it is finding a problem with your hard drive. When BIOS goes through its start-up.To me ( I am no pro ). The hard drive should be what the BIOS boots first. Try these,When you start your computer,hit the # key that takes you in to your BIOS. At the bottom Push the F key that say's "restore defaults",yes should already be highlighted.Push the F key that say's "save changes". Remember,in BIOS,you have no mouse-press enter after each. Go into windows system tool's and run scan disk to see if it finds an error on your drive-both standard an through options.check the box that say's automatically fix errors before you start.

seems like ur hard drive has just started to run into some problem, so its better to backup important files and check if ur warranty is still valid.

and as a preventive measure, hard disk problems mainly occur due to voltage fluctuations which damages the sectors. so, its better to have a ups and check the earth connection to ur plug point by an electrician.

ps:and last , i shld say, u ve framed ur question really well, using the most apt words. say, are u a lawyer ,or, u working for some concern dealing with legal issues???

I had this problem before. Your hard drive is still usable but not in too good shape. The best thing to do there is to do a backup of your documents and all important data and get your hard drive replaced. You may still have your hard drive under warranty, either under your manufacturer or under the hard drive company itself, if you bought it less that three years ago.

Never seen that before,but seem's like your system is doing somekind of check.i have had some like it but not that one.I only got it once.It was just a system test of some kind.Check with dell support if it continues.