The hard drive is failing.  Backup your user data immediately to some other device such as CD's, USB "memory key" or external hard drive. 

The "S.M.A.R.T." is an internal disk monitoring system for the health of the the hard drive.  Start looking for a new hard drive immediately.

Thanks Fireberd,

Exactly how do I physically "Backup" my user data to CD's, USB memory key or Ext Hard Drive?

How do I that?

"User data" are items such as pictures, music, wordprocessor files, e-mail address book , etc.

You can copy (backup) these items to a CD-R (if you have a CD burner), to a USB "memory key" (depending on the capacity of the USB unit), etc. 

If you copy the files to a CD-R (NOT a CD-RW) just make a "data CD" with your CD burning program.

The user data, if you want to save it, will be lost when you install a new hard drive and do a complete reinstallation.  HERE is the Dell instructions on a "reinstall" (which is basically the same as a new install with a new hard drive).

Thanks again Fireberd, that information is excellent and I'm very grateful.

One other question;

My current (faulty) Hard Drive is a Maxtor 4D040H2 40GB IDE 5400RPM, which I've discovered via the web, is a problematic make.

Dell have suggested that I replace it with one of their "Origin Storage" types:Part No# A0787953, which is an 80GB IDE but runs at 7200RPM.

Would you consider this OK to use on my Dell Dimension 4500, especially as it runs at 7200RPM instead of 5400RPM?

That replacement will work OK  and actually be a little faster on disc access.    Actually any IDE drive will work, you don't have to buy it from Dell.  There may be some limitations on the size of the hard drive (BIOS issue) but other than that, any standard IDE/EIDE (PATA) drive will work.  Western Digital is my drive brand of choice. 

Fireberd,

Once again, many thanks for that info, I shall investigate the Western Digital Hard Drives.

One other problem has come up.

I've saved my Files as a data CD with no problems but when I went to use "Files & Settings Transfer Wizard" and after selecting "Old Computer", it came up with a message to turn off my "Windows Firewall" - which I did but then, after several more seconds, it came up with an Error message: "Files & Settings Transfer Wizard Has Encountered A Problem And Needs To Close".

I clicked on the details of the error and this was the report: Event Type: InPageError. P1:c000009c  P2:00000003 and then it revealed this detail:

C:\DOCUME~1\ANTHON~\LOCALS~1\Temp\WER4440.dir00\migwiz.exe.mdmp

C:\DOCUME~1\ANTHON~\LOCALS~1\Temp\WER4440.dir00\appcompat.txt

So my questions are:

1) Are the errors fixable

2) Should I not transfer/save My Files & Settings and just install the new Hard Drive and then re-install all my previous Programs from the original Disks etc.

Thanks

SUCCESS!!!!

Many thanks FIREBERD!

Just fitted a Western Digital Caviar SE WD3200AAJB 320GB IDE Hard Drive and reinstalled all programs and my computer is not only working but it's better than before.

Many thanks for your advice & guidance.

Cheers from the UK!