If your computer can't boot, here are some things to try. All
answers are taken from the blog.
If you have Windows installation CD
One simple way to tell if you have the Windows Installation CD.
There's only one installation CD. Only one disc is enough to
install XP.
However, if you have a couple, most likely you don't have
Windows Installation CD.
Please also note that it's a CD, not
DVD. The answer is obvious. DVD storage space is
much higher than a CD, thus everything is able to fit into one. If
you boot up to the DVD and it formats everything, that's your
problem.
Step 1
Configure your BIOS to boot up from the Windows CD.
Please refer to this tutorial if you've no idea how - http://www.hiren.info/pages/bios-boot-cdrom
Before saving the settings, insert the Windows CD in.
Save the BIOS settings. Depending on your configuration, it will
either restart your computer or continue.
Step 2
If you've changed the BIOS settings successfully, you'll get a
prompt to press any key to continue. Press Enter or some other key
that you like.
Windows will load start inspecting your configuration and loads
its usual stuffs. Be patient.
Once done, you will see this screen:
Press R.
You will be prompted to select an operating system to repair.
For most, there should be only one operating system installed and
to choose from.
Just press 1 to continue.
Wait a while. You should see this screen next if your
administrator has no password. If it has one, please enter the
password to get to the screen as shown below.
The difference between the above and the previous is the
presence of this line: C:\WINDOWS >
Type in disable IntelPPM and press Enter.
You will get this screen:
After that, type in exit and press Enter to
restart your computer.