Please help me install [duplicate]

Yes, it is always a good idea to make a backup/image before messing with the hard drive in a potentially dangerous (data wise) way.

There are a lot of people that can help you. I would start with disabling UEFI in the BIOS, then booting off the live disk.

Lubuntu is a fast and lightweight operating system developed by a community of Free and Open Source enthusiasts. (lubuntu.net) if this sound interesting to you, then try it. The cool thing about Ubuntu though is you can install all the Desktop Environments and use the one you want at any given time, without having to re-install your OS.