virtualbox.org

I show I downloaded virtualbox 5.0.2-102096 on Aug 20, and just installed it. I say this because I only see 5.0.1 on their website now. Anyway I installed it and tried to install windows 7 64bit as a virtual machine. It will not install, I get "no bootable medium found! system halted". I can look under devices-optical drives and see I have a win7 iso file listed as drive, and under settings-storage it is also listed. Under settings-system the boot order lists optical first. What have I missed? I did install the expansion pack too. At first it said it failed but on the 2nd attempt it says it is installed.

I don't know what website you are looking at, but the official VirtualBox website is currently offering 5.0.10 .

If you have the iso assigned to the optical drive and the vm is set to boot from it, the only explanation is that your iso file is not a bootable file. Where did you get it from?