Re: INSTALL UBUNTU-12.04.2-desktop-amd64
The downloaded ubuntu.iso has to be 'burned' to the USB and not copied or transferred. The tools suggested by 'VMC' should help you do just that, burn the .iso to USB.
The important thing to note before installing Ubuntu is your current Hard Disk Partition Scheme. If you are using 'msdos' Partition Table then you have a only 4 Primary Partitions limit. If you already have four Primary Partitions then you have delete a partition and re-create that partition as Extended Partition. An Extended Partition is a Primary Partition which acts as a container for Logical Partitions. Within an Extended Partition we can create more than 100 Logical Partitions.
** Windows Partitions MUST be managed from Windows only using Windows Disk Management tools.
Once you've prepared and burned your Ubuntu.iso to the USB, boot with it and 'Try Ubuntu without Installing'. This option lets you to try Ubuntu before installing. Let the desktop load, then open the TERMINAL (Ctrl+Alt+T) and run the following command:
... and post its output here. It will also help if you can post a Screenshot of your HDD and its partitions from Windows.
"Evolution is Nature's way of issuing upgrades."