I have not been prompted to upgrade to 8.1, & when I check for updates, it says no new updates are available. Didn't 8.1 officially come out last week?
Use the Desktop Windows Update Control Panel and install the updates (may come in two batches and one may be a Firmware) reboot and then open the Store and it should be there.
I upgraded 8.0 last night on my SP1 and everything went as smooth as butter, even with programs like CS6, Lightwave3D, Office, and Painter X3 installed. I lost nothing.
Just remember to remove any external accessories, as well as the Micro SD card if one is inserted, before installing the update and you should be fine (I even removed the keyboard). If you leave anything connected (or inserted) to the main tablet, your mileage may vary.
ok,ty...all worked well. Only issues so far, doesn't recognize my finger touch in google chrome sometimes & i have to use the pen. My bookmark toolbar is tiny, cant remember how to fix it.