No you do not need it with XP For anyone interested here is a review of Classic Shell to help you understand it better.

What I've read and understand... windows automatic updates installs the store item for you to decide to install or not from the store the 8.1 upgrade. I assume it will be much like 8.1 preview and if it errors on the live login it defaults to a local non email login. Many were using felonious email account names just for that purpose. 8.1 preview you can right click folders and/or files and tell it skydrive or not or both by save local copy. Which I use the local copy only on things I use frequently. I would hope the final 8.1 will do that save local copy automatically for a few days unless manually checked or marked not to.. They're still not finished with 8.1 final. So nobody knows the changes we will see on Oct 18 ,... probably as an upgrade to the RTm and download intergrated install withl at 8.1 upgrade or fresh iso upgrade last moment download install. This post was edited by mikie on Thu, Sep 26, 13 at 23:45

The Zenbook UX303LN is now history. After the upgrade to Win 10 the touchpad driver would not stay installed. Each time the laptop was powered off, then restarted, the touchpad driver would have to be reinstalled. This is a known problem to Asus. I talked to Asus several times today, and also to Microsoft. Neither could provide any solution. I've spent hours on the phone to Asus and Microsoft trying to get a virtually brand new laptop to run correctly after "upgrading" to Win10, which apparently does not like Asus Zenbooks. I called Asus and Microsoft today to tell them I give up. I'm not spending all my free time on fixing this. After I got off the phone, I took a hammer to the laptop and jumped up and down on it. It's in the trash and headed for the landfill... I'm getting out my Mac Book Pro now....

I dunno but, windows 10 current build, the typical restart isn't a full restart anymore. It saves or cache's some of the store apps and system configurations & at restarts opens them in the previous running configuration. After you do install your shell program - You might click a blank spot on the desktop, to give mouse focus to the desktop, and use the key combination ALT+F4 to open the shutdown menu then select restart. Which will be the full restart not saving any Store apps / or other system configurations.