Does "Replace Current Linux Systems" do as it says?
I've been using GNU/Linux for around 4 months now, and I love it. On my desktop I've first started off with Ubuntu, then to Mint, and then back to Ubuntu. On my Laptop, I use it for experimenting so I've used Fedora and currently Arch Linux *In which I have tons of fun learning how to get everything set up.* I dual-boot Windows 7 with Ubuntu, and if I knew how to flawlessly partition, I'd definitely be using other Distributions, but Mint and Ubuntu have the easiest partitioning. Any way, I've been wanting to install Sabayon, the Gentoo derived User-Friendly distro, to replace Ubuntu, and I want to know if the "Replace Current Linux Systems" option would flawlessly partition it and not effect my Windows 7 Partition. *I don't want to lose Windows 7, I don't have an Installation CD to recover from if I did, and even if I did, I wouldn't have a License Key either*
Another option, would it be easier to first delete Ubuntu and GRUB, and set my MBR back to Windows' Boot Manager, and THEN shrink my existing partition of Windows to 500GBs so I can tell Sabayon's installer to use all the free space? Is there a possibility that it could mess up during the Install? I'm a bit worried I might mess something up. On the harder distros *Like Slackware, Arch Linux, and Gentoo" I do a full install either on my laptop or in a Virtual Machine. I've never partitioned manually before.
Summary: Will the "Replace Current Linux Systems" option in Sabayon Linux only overwrite Ubuntu, and not touch Windows and have no chance of failing? If it does have the chance of failing, what is ratio/percentage? Should I shrink Windows partition inside of Windows *Since surely Windows wouldn't corrupt itself... would it?* and assign Sabayon to that freespace instead? Once again, I can't afford to take huge risks. I have never manually partitioned before either.