Hello Thequietone, and welcome to Seven Forums.
Yes, you sure could buy a new Windows 7 to do a clean install
with if you wanted to.
Before you do, be sure to have all of your laptop's drivers
downloaded and saved somewhere (ex: USB flash drive) to have ready to install when you are finished installing Windows 7. You should be able to get them at the laptop manufacturer's driver
download page for your specific laptop model.