Computer won't start in safe mode or any mode

Computer: almost 7-years-old; 2-year-old hard drive, running XP Home.

Background:
Everything seemed to be fine and then ...
A message came up saying there was a Service Pack 2 installation available. I clicked on the message and let it download while I left the house. I get back and the computer has a message on it saying it needs to reboot. I let it reboot and now it won't start.

The machine goes from the black background window that says Microsoft XP to the blue background window with a drawing of some electronic part and back to the back window over and over again.

When I push F8, I get the expected window, BUT it won't let me start in any of the safe modes and won't start using any of the other commands listed. Sometimes, it runs through a list that appears to have something to do with the hard drive. I only remember part of it. I believe the list includes "disk 0; partition 1; and a bunch of other stuff on each line.

I've tried starting and restarting with the Windows XP in the CD drive. I've tried shutting down the computer and leaving it alone for an hour then starting it again with and without the XP disk in the drive.

Any other ideas? (please note that I am not a computer geek by any stretch of the imagination!)

 

Reboot, tapping the F8 key to go to the advanced boot options.

Choose 'safe mode'

If this boots go to start>controlpanel>add/remove programs (tick the updates box)
remove the sp2 update

If it doesn't boot

Choose 'lastknown good configuration'

press enter

If this does not work you are in for a reinstallation of Windows.

 

None of the modes on the F8 page work. So, the next question is: How do I reinstall windows from my CD? I haven't a clue how to get the machine to read the disk. I've tried rebooting with the disk in the drive but that doesn't work.

 

Reboot the pc tapping the Del or F2 key or as instructed on the screen to go to the bios, also called setup.

When the setup screen opens look for something called boot order or boot priority. This may be one or two options screens deep.
Set it to boot from CD first.

place the Windows CD in the drive.

Go to the exit screen, save the settings and exit.

the pc will reboot.

Watch the screen
At the prompt 'press any key to boot from CD'
Press the space.
If you miss this it will go back to the hard drive.

When the Windows setup screen opens

Accept the licence
Press enter at the next screen to install - not R for repair console.
At the next screen
Press R for repair installation, not enter for fresh install.
A screen will open showing the windows installations and asking which to repair.
choose yours (the only one?)
press enter and follow the instructions.
Input the windows key from the side of the pc if you are using a windows disk from somewhere else.

Doing it this way will preserve any data but break any antivirus program and windows update will have to be reinstalled. Most other programs will still work.
However after a failed SP2 install the repair option does not always work.

Let us know how you get on.