Microsoft has become so confident with the speed of their Windows 10 Upgrade that they're offering a free Dell Inspiron 15 if your existing PC isn't on it within the day. Users have to bring their device into the store for the update to reap the possible benefits.
The PC also has to meet all of the hardware requirements for Windows 10, so using a twenty-year-old dinosaur desktop won't work. They will, however, recycle your PC and give $150 towards a new one if it's incompatible.
Naturally, you have to arrive at the Answer Desk before noon to be eligible, or the system would be exploited by people turning up right before close.
It's unlikely that anybody will be able to win this challenge, but it's clear that the true goal is to get as many people on Windows 10 as possible. The company has come under fire recently for their aggressive push of the product, losing a $10,000 legal battle as a result. This scheme, at least, doesn't rely on trickery.
The offer runs until July 29th and is available in Microsoft retail stores in the US, including Puerto Rico and Canada. A tool on the offer page will tell you if there's a store near you, as well as giving more terms and conditions.