Re: can't install 11.04 version
If you are determined to continue with this, then BEFORE you do anything else, do yourself a favor and use the Backup feature in Win7 to create and burn a Win7 Repair CD.
That will prove invaluable later, should something go wrong during your dual-boot setup and you have to repair the Win7 boot loader, or you simply want to remove Ubuntu and restore your original Win7-based MBR.
Ubuntu 15.04 Mate, Mint 17.1; MS Win 8.1, Win10 TP.
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