Today I got a message I can download Mavericks on the App Store for free and install it, upgrading from OS X 10.7.5. I did so but then got the message that I can't install Mavericks on my HD, for the exact message see the attachment. Beofre it told me that I am using ths volume for TimeMachine backups, which I don't.
Maybe of impoartnce: When I bought my MacBook I had the original HD exchanged with an SSD HD, might that play a role?
Thanky for any hints!