Is your laptop fairly new?
I cannot help you with anything else that you haven't already tried, but I believe I could you with your installation to make that much easier and painfree.
First, you should have a good backup program and use it. Then when this happens that you cannot startup your laptop like this, you could easily do a recovery.
After you have followed Griff's suggestions to format the hard drive, check with your manufacturer's website, by clicking on "Support", and then "Download Drivers and Manuals" and then read the manual for your laptop for "Recovery". There should be a "magic key" or key combination to press at startup to bring it back to factory settings.
You didn't tell what kind of system you have, so I can't look it up for you. However, on my Acer Aspire 5739G, it is Alt + F10; on my son's ASUS laptop, it is F9; and on a lady's Compaq that I just helped her with, it was F11.
If you can find out what your "magic key" is, that will not only install Windows, but it would bring the laptop back to exactly the way it was when you brought it out of the box--even with all those nuisance programs installed. However, all the drivers would already be installed, so you won't have to go to the manufacturer's website and download them and then install each one individually.