Need Help With Installation!

[e_rag922]

Ok, I'm trying to install portal 2 (I have had it installed before but I got a new PC so...). It says I don't have enough disk space (which is true) but I have plenty of space to install it on a jump drive. I tried putting the portal 2 file into my flash drive file and tried installing it there but to no avail, it didn't work -_-. So if anyone can help me and tell me how to install it to a flash drive I will personally make you some pancakes.

Thanks,
DEMO-THE-MAN