In case you happen to own a tablet with Windows 8.1 installed chances are your device might also run preview version of Windows 10. Before setup you need to gather some information. Read on and check if you are ready to take the next step and install Windows 10 preview.
Acer Iconia W510 laptop and W4-820 tablet are almost similar
Tablets are not necessarily that different from PC's. An example: my Acer Iconia W510 hybrid laptop (see picture below) runs Windows 10 Preview. Acer Iconia W4-820 has almost the same hardware inside as W510. They both can run Windows 8.1 so why not Windows 10 preview as well?
Make sure your tablet has Intel x86 processor inside. IMHO it's the best choice. ARM architecture will not take you too far and is actually out of question (well, Raspberry Pi 2 with ARMv7 is told to run Windows 10...)
W4-820 tablet has 2 GB RAM. It's capable of running 32-bit version of Windows 10 Preview. 1 GB RAM might also do but the more memory the better.
My laptop W510 has a modern BIOS. In order to enter the BIOS you have to push Power + Vol Down at the same time. Next Secure boot has to be disabled and F12 enabled. Save and Exit. It took some time to figure out how W510 BIOS works.
Windows 10 preview ISO
Become a member of Microsoft Insider program. You need Microsoft account (it's free). After joining download 32-bit ISO image.
4 GB bootable Windows 10 preview USB stick
Try Rufus. It's a free tool (works on Windows) which writes Windows 10 Preview on 4 GB (absolute minimum!) USB stick. Make sure you choose UEFI. Rufus also makes USB stick bootable.
Not all devices work out-of-the-box after setup! However you can download Windows 8.1 drivers beforehand and save them on USB stick. That way for example touch panel and wifi wake up.
W4-820 has only one microUSB-port. You'll need so called OTG cable (On The Go) which converts microUSB to normal USB.
If you want (and you do want!) to attach USB keyboard and mouse after setup at least USB 1.1 hub is needed. When drivers are installed you can remove additional devices.
When installing Windows 10 preview make sure NOT to erase Windows 8/8.1 recovery partition in case you need to downgrade to Windows 8.1. How come? Why do you want to go back? Well, everyone with fully working version of Windows 8.1 are allowed to upgrade to Windows 10 RTM later this year. And hey, for free! No charge!
Famous last words
Have some coffee. Mediation. Chewing gum. You are going to move forward at your own risk! However Windows 10 preview on touch panel is great fun! Besides Office touch apps (Word, Excel and PowerPoint) are waiting for you in Store beta which you can find inside Windows 10 Preview (for free!).
Acer Iconia W4-820
Acer Iconia W510 with Windows 10
Preview setup starting