TAMMARA1 you need to DOWNLOAD BLACKBERRY OS FOR 8320 4.5 iknow u downloaded DESKTOP MANAGER 4.5 but u also need to download n install the blackberry OS 4.5 for 8320 to ur PC thn delete the vender.xml n thn plug ur bb to computer n open ur DM n it will tell u tht new update is available n thn follow the instructions