If I re-install Windows, will it ensure that all types of malware/spywares/rootkits and any other malicious software are removed from my laptop?
Absolutely no. It goes back to the "chicken and the egg" thing.. One of the things that Microsoft as well as other vendors warn against is installing/re-installing the OS when you have a virus/malware/or other rogue software. You ** MUST ** have the "bad software" removed and/or disinfected first. It is like the company who is re-paving your street, if they don't take care of what is causing the pothole, it will assuredly be back. Why do you think when the builder of building takes so long on the foundation? It has to be solid. Same thing with your computer, it has to have a clean and solid foundation as well. Re-installing/upgrading an OS is never recommended to remove/clean a system.