There is an HP slate called the HP Slate 500, which I believe has Windows 7 installed on it, and probably should be able to do most of what you want, but it was very expensive. I am not even sure if HP is still making them, though it hasn't been out that long. (This slate is also totally different than the TouchPad tablet they discontinued).
Other than this, I don't think there is an Android tablet either that can do everything you want out of the box. There are probably apps you can download to be able to do most of it. As for reading books, you can download the Kindle, Barnes & Noble, Google, and other reader apps to read all those books. There are many, many note programs on Android, Evernote being a very good and popular one; There are also quite a few office apps that are compatible with MS Word, Excel, etc, but these are more pricy. As far as files generated in early versions of an OS working with future upgrades, that doesn't even always happen with Windows on a regular PC. I know I've had apps become incompatible with Windows upgrades. So I don't think any OS could guarantee that.
Of all aspects of personal computing, I like slates or tablets the most. And of all the os out there I have stuck to Windows, mainly bcause it is the most familiar, and in my limited expeience, has the most features I desire. In fact, I have never used an Android tablet and know almost nothing about it.
But I am now wondering if other tablet forms using the Android os are also capable of doing the same things I love with the Win 7 slates: These are: (1) the ability to take realisic hand-written notes and save as such, or convert to text(2) be able to read books of all formats: Mobipocket, Adobe digital Editions, Zinio, MS Reader, Kindle, all in one device, (3) be able to play any video in any format or be able to install any missing video apps (4) can read and edit Excel and Word documents, (5) that I can easily share my files with friends with no compatibility problems and (6) that all files generated in earlier versions of the os will work with future upgrades of the os.
I am no expert, and what I have written here may be very basic to most people, but can I use the android systems for these functions? Which of the android tablets is best for me?