At the moment it's a bit like you asking directions out of there, but you can't explain where you are to us - so we don't know where you are either.
There are 2 different scenarios - trying to start up the PC, and trying to install or reinstall Windows - let's try to keep them separate.
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If you just start the computer up - what happens?
Normally, if all is going well, the BIOS/PCManufacturer splash screen comes up then Windows starts to load and eventually you get a desktop. If you don't get a desktop, you get a black screen with a range of options of different ways to start your computer including safe mode. If Windows does not load, you get an error message.
Which of these is your situation? If there is an error message, is it the missing hal.dll one at this stage?
Have a look here:
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Another situation, if you are trying to install windows:
If you are trying to install Windows, you have a CD in the drive when you reboot, and after the BIOS, you are usually asked if you want to start from the CD, and when you press enter, the blue setup screen appears, and the setup process starts. Is this happening, or are you getting error messages here? After loading a bunch of files, Setup starts to ask you questions - how far do you get, and what keys do you press?