Jul'29 2015 is a date to look out for when Microsoft launches Windows 10. So if you have a PC which qualifies for the upgrade, then that date is not far enough.
While here is the FAQ's link from Mocrosoft http://answers.microsoft.com/en-us/insider/wiki/insider_wintp-insider_install/frequently-asked-questions-windows-10/5c0b9368-a9e8-4238-b1e4-45f4b7ed2fb9 , I will share a pic which makes your job easier.
So if your taskbar shows a small white windows icon above, your PC qualifies for the upgrade. Though reservation is not compulsory, I would suggest to reserve your copy so that you receive your copy at the earliest. You need to right click on the icon and select the option to reserve your copy. While this upgrade is free for most of us, there might be few PC's for whom this is not free. Do read this document - http://www.zdnet.com/article/windows-10-upgrades-wont-be-free-for-everyone-do-you-qualify/
Once you reserve your copy of Windows 10, you receive a confirmation mail from Microsoft. While I wait for the D-day, one important thing to be noted is to ensure that you have a good broadband with a healthy download limit. Microsoft tells that the download will be around 3 GB. While I still try to figure out how to download a single copy and use across devices, you go ahead and reserve your copy now!
