"OSX Mavericks cannot be installed on this computer"

I recently had to replace my MacBook Pro5,5 hard drive, and as such had to reinstall the operating system. I installed Snow Leopard, which came with my mac, updated in order to get the App Store back, and then downloaded OSX Mavericks; yet when I go to install I receive a prompt saying it "cannot be installed on this computer". I had Mavericks on my MacBook Pro before having to replace my hard drive, so am at a loss as to why this is happening?! Can anyone help?