Actually its this easy nowadays:
Step 1:
Put in Windows Installation CD, wait untill it says: Press any key now if you wanna start with the Windows Installation CD (or something like that) Obviously you press the button and the installation begins.
Step 2:
You will now get to License agreement, press F8 and type in the cd key.
Step 3:
The installation will now ask you wether you wanna do a clean install, or repair, obviously you wanna do a clean install.
Step 4: Delete previous partitions for example; "C: or D:"
Once everything is deleted choose create new partition, use all disc space (easiest alternative) press enter, done!
Step5: Follow the installation, set timezone easy as pie, let the installation do the network settings for you automaticly.
Step6: Install drivers preferably the newest ones from the manufacturers website but if not with the CDs that came with the computer.
Then you are good to go!
If any problem just send over a plane ticket and ill be delighted to fix it for you
