If you bought sonar 8.5 it will have both versions on the installation disk. When installing on a 64 bit machine with a 64 bit os, you'll be given the choice between them. Gord ----- Original Message ----- From: Julie M. To: ddots-l@xxxxxxxxxxxxx Sent: Sunday, January 30, 2011 10:10 AM Subject: [ddots-l] sixty-four bit Sonar Hi. I bought Sonar 8.5 for 32 bit computers. However, I need to purchase a new computer, and it will likely be 64 bit. Do I have to repurchase the program, or can I download the sixty-four bit version? Thanks.