Are you able to connect your computers to each other.
If you are, then you can use "internet sharing".
I did this when I was reinstalling Windows on my grandparent's computer. They had dial-up and I wanted to use the updates faster. So I wirelessly connected my laptop to high speed, then connected their computer to my laptop. After that they were using high speed internet, until I unplugged them
Anyway, if you have a way to connect the two computers to each other (whether wirelessly or wired) then you can try internet sharing.