Get a Flash Drive/Memory Stick.
They are as cheap as chips!
4G for $25, 8G for $35, 16G for $60 where I live.
Plug it in to the USB port, let it be recognised; when autorun starts>
select take no action> minimise it.
Go to what files you want to copy to the other computer> right-click on the
files>Send to>USB drive.
Click Safely Remove Hardware>Plug into other computer>etc, etc> copy files
from it to My Documents
To select multiple random files hold down CTRL when selecting files to copy.
Or SHIFT, to select top file to last gfile you want, and all in between
Or, click on Edit>Select All