I need too install a broadcom sta wireless driver and since the internet doesn't work without it I figured I'll have to make a deb.
How can I make a .deb in windows precisely?
Although if you really need there are two ways, the reliable one, although it spends more time, and the fast one, although not the most reliable:
Use a Virtual Machine
Install Ubuntu on a Virtual Machine, if don't know how to do it, see This Guide.
Then just create your .deb, if don't know how to do it, see This Guide.
See that if you are not familiar to creating .deb files it will be very complicated, difficult and frustrating accomplishing what you want to.
If you don't feel very confident about creating .deb files you shouldn't opt for the Fast method.
In addition I guess that if you try to install your drivers in a LiveUSB (it can´t be a CD/DVD, and the LiveUSB needs to be created with some space to store changes made) and then install Ubuntu through the LiveUSB you will have your drivers installed easily, but it´s just a shot, not sure if it would work.