Detective needed...any ideas?

My apologies for the long post but I wanted to give you a good picture of what's going on. It's a Dell Dimension (about 4-5 years old) with XP Home. Is this signs of a hard drive failure? Sincere thanks in advance to those who reply.

 

Ok, every day is different when I go to start the computer...............so will go

over the past couple of days with you so that you have an idea of the

non-existing "pattern".

DAY 1
1. Push the big start button and computer begins it's quiet hum......the same

quiet hum that is constantly on the entire time the computer is ever on.
2. Light on my CD drive (drive F) comes on.
3. Light on my DVD drive (drive E) blinks twice
4. Light on CD drive goes out
5.  Then absolutely  nothing...........no new noises, no lights  on and nothing

appears on my screen.
6.  I push the restart button on the tower.
7.  Light on DVD drive blinks twice and I hear two clicks.
8.  DELL screen displays on my monitor
9. Light on the CD drive blinks once.
10.  I hear a short purr and then one beep.
11.  Windows XP screen appears and the computer then is on and stays on. 

No error page, just starts up and loads everything as normal.

DAY 2:
1.  Push the big button to start computer and hear the hum that is there

whenever the computer is turned on.
2. Light on CD drive light comes on.
3. Light on DVD drive blinks twice and light on CD drive goes off.
4.  Light on DVD drive blinks twice and I hear two clicks.
5.  DELL screen displays on my monitor
6. Light on the CD drive blinks once.
7.  I hear a short purr and then one beep.
8.  Then nothing happens..............no more lights, no new sounds and nothing

appears on my screen.
9. I hit restart button.
10. Light on CD drive light comes on.
11. Light on DVD drive blinks twice and light on CD drive goes off.
12.  Light on DVD drive blinks twice and I hear two clicks.
13.  DELL screen displays on my monitor
14. Light on the CD drive blinks once.
15.  I hear a short purr and then one beep.
16. Then I get the black screen error page that says Windows did not for

some reason start properly.  It gives me 26 seconds to read the page which

says it could have been a power failure, a shut down to protect files, you may

have hit restart or you may not know why it happened.  It gives you options

for restarting and I just leave it at "Start Windows Normally".
17. Then the Windows XP page comes on and the computer loads everything

and is ready to use.

DAY 3:
1.  Push large button............hear the tower hum quietly.
2. DVD drive light blinks twice.
3.  Then nothing..............no noise, no lights, nothing on screen.
4.  Hit restart button.
5. DVD drive light blinks twice.
6. CD drive light blinks once quickly.
7.  Nothing................no noise, no lights, nothing on screen.
8. Hit restart again.
9. DVD drive gives me on blink.
10. CD drive light comes on for a longer time then goes off.
11.  Nothing.............no noise, no lights, nothing on screen.
12. Try restart one more time.
13. DVD drive blinks twice.
14. CD drive light comes on for longer time then goes off.
15.  Nothing again.
16.  Unplug computer and leave for about 5 minutes.
17. Plug computer in.
18. DVD drive light blinks twice.
19. CD light comes on for a couple of seconds and then goes off.
20. DVD drive light blinks and I hear 2 clicks.
21.  DELL screen appears on Monitor
22. CD drive light blinks once and I hear 2 clicks.
23.  I hear the short purr and one beep following it.
24.  Windows XP screen comes on and the computer loads and is ready to

use.

DAY 4:
1. I push the button to start computer and hear the quiet hum.
2. CD drive light comes on.
3. DVD drive light blinks twice.
4. CD drive light goes off.
5. DELL screen appears on monitor.
6.  CD drive light comes on and I hear 2 clicks.
7.  I hear one purr and then a beep.
8.  Nothing.........no noise, no lights, nothing on screen.
9.  I hit the restart button.
10.  CD drive light comes on.
11. I hear 2 clicks and the light goes off.
12.  I hear the purr, and then the beep.
13.  Windows error page comes on telling me that Windows did not start up

properly.  The 26 seconds pass.
14.  Screen goes black and nothing happens.
15.  I hit restart once again.
16.  CD drive light comes on.
17.  I hear the 2 clicks and the light goes off.
18.  DELL screen appears.
19. CD drive light blinks once.
20.  I hear 1 click.
21. Then I hear the purr and then on beep.
22.  Windows error page appears on screen and stays for the 26 seconds.
23. Then the Windows XP window appears and the computer begins to start

normally and be ready for use.

TODAY:
1. Push the big start button and computer begins it's quiet hum......the same

quiet hum that is constantly on the entire time the computer is ever on.
2. Light on my CD drive (drive F) comes on.
3. Light on my DVD drive (drive E) blinks twice
4. Light on CD drive goes out
5.  Then absolutely  nothing...........no new noises, no lights  on and nothing

appears on my screen.
6.  I push the restart button on the tower.
7.  Light on DVD drive blinks twice and I hear two clicks.
8.  DELL screen displays on my monitor
9. Light on the CD drive blinks once.
10.  I hear a short purr and then one beep.
11.  Windows XP screen appears and the computer then is on and stays on. 

No error page, just starts up and loads everything as normal.

SandyBeaches...