puting a dongle intothe acer emachine

i put my telstra dongle into my lil notebook then i bought the acer e machine and it dident work first time i put it in it just dident do anything and when i tried a second time it said mobile card busy iv realy got no clue when it cums to tech any help would b very apreciated thanks every1

hard for us to comment as we've no experience of the software used on Australian networks

As a general comment, before you do anything else, speak to Telstra and see what they say.
As the Acer is new, is there any chance the USB ports on it are faulty? Could be worth speaking to their support line as well