+ 0 Votes try a secondary install databaseben 2 years ago if the version of the win cd is different from the version on the computer, you won't be able to use the repair installation method that the cd would otherwise provide.in other-words, if your cd is win7 but the computer was updated to win7 sp1, then sp1 would have to be uninstalled in order to downgrade your computer. then you would be able to use the win7 cd to repair your win7 system.however, what you can try is to proceed with doing a full install of win7 via the cd but install it onto that hdd that use to have ubantu. so during the installation process, be sure not to run away with the enter key and instead read each screen carefully and be sure to target the secondary hdd for the installation. otherwise, the cd will select the default hdd and over write it. there are benefits with proceeding with a secondary installation. it will create a dual boot manager whereas you will be able to boot to your old o.s. as well as the new one you just installed. but if you can't boot to the original o..s, then at least you can use the new installation to retrieve your personal files.