Microsoft sells a copy of Windows 10 Home for $139 and yet if you don’t mind getting a free new PC that you can carry around, it is worth looking at the Z83II, a $95 (yes $95) mini PC from popular Chinese retailer, Gearbest.
Now there have been cheaper PCs in the past but they usually have one massive flaw; they are either second hand machine or they suffer from insufficient memory and onboard storage (they usually have 2GB of RAM and 32GB storage).
The Z83II is the most affordable Windows 10 PC we’ve found to date. It has an old but still capable Intel Atom X5-Z8350 quad-core CPU, 4GB of DDR3L RAM and 64GB of eMMC onboard storage.
It is well connected as well with a bevy of ports; you get a Gigabit Ethernet port (a good surprise at this price), 802.11ac (might be an anomaly), Bluetooth 4.0, a HDMI port, a card reader, three USB ports (only one USB 3.0) and a headphone jack.
The device is absolutely tiny, hardly bigger than a couple of stacked CD cases (remember these?) and you even have a bracket to mount it at the back of a monitor or TV.
It is passively cooled which means no annoying fan noise when watching a TV. You won’t be able to upgrade it (say by swapping the SSD) though as everything inside is integrated.