Need help quickly

Alright heres my problem. im over at my cousins house and my computer is too slow to download the main runescape files and i need to figure out how to set the runescape main files to download to my flash drive instead to this computer. any answers to my problem? help appreciated!

 

if its too slow to download the main file.. u wont be able 2 play at all... i have a comp that can download main file but it wont even let me log into rs without losing connection.

 

it can download the main file but since im on dial up i dont want to wait for 45 minutes to play for about 15

 

Hmm drag the jagex filestore folder from a system folder in the C: drive. Sorry I've forgotten which one.