I'm going to a friends house for a day and we are probably gonna stay up all night and I was wondering if you can move the whole DBO folder into a flash drive and take it over to his house to play without installing it? When I used to play Maplestory it worked fine but i'm not sure about DBO.

I think you need to install the game initially. Just install a client that's at least v1.5.0 then copy and paste your DBO folder and replace all existing files.

Just copy and pasting might work as well. If you try this, could you please let me know how you go as I will be needing to install DBO on a new machine soon.