Better than my options. I have a desktop that got infected with a virus somehow. During my efforts to get rid of it I did something and now the OS thinks it is a pirated copy. I eventually just gave up and bought Windows 8 to install and get rid of the virus. The installation program gives me the options of erasing all the applications I have installed, and erasing the entire filesystem. It won’t preserve my applications. That’s great for getting rid of the virus, but I also have legit copies of Visual Studio and SQL Server that I will lose, and are expensive.
Your Windows and other software are your licensed copies.
You should not have to re-purchase anything, including the OS.
Check with Windows support — they can be pretty helpful at times.